Venus's middle cloud layer is the most Earthlike place in the solar system apart from Earth**, is energy-abundant, has favourable orbital dynamics, easy entry, and the simple act of storing electricity for the night via reversible fuel cells - if plumbed in a cascade - can enrich deuterium (2 1/2 orders of magnitude more abundant on Venus), a natural export commodity, if launch costs are sufficiently low. The atmosphere contains CHONP, S, Cl, F, noble gases, and even small amounts of iron. Pretty much everything you need to build a floating habitat, which can be lofted by normal Earth air, aka people can live inside the envelope. Aka, unlike on Mars, where you live in a tiny tin can pressure vessel where any access to the outside tracks in toxic electrostatic dust and you waste away from low gravity, on Venus you'd be in a massive, brightly lit hanging garden, where you could live half a kilometer from a crewmate if they really got on your nerves.
Most Earthlike? Yes. Temperature, pressure, gravity, etc all similar. Natural radiation shielding equivalent to half a dozen meters or so of water over your head. Even storms seem to be of an Earthlike distribution. The "sulfuric acid" is overblown; it's a sparse vog, with visibility of several kilometers; with a face mask, you could probably stand outside in shirtsleeves, feeling an alien wind on your skin, only risking dermatitis if you stayed outside for too long.
Indeed, it'd actually be useful if the sulfuric vog was more common (to be fair, it's still unclear whether precipitation happens, and if so, whether rains or snows; the Vega data is disputed). Why? Because it's your main source of hydrogen. Highly hygroscopic and easily electrostatically attracted, so readily scrubbed through your propulsion system. First releases free water vapour when heated, then decomposes to more water plus SO3, and if you want you can further decompose the SO3 over a vanadium pentoxide catalyst to O2 + SO2, or you can reinject it into the scrubber as a conditioning agent to seed more water vapour. Of course, if precipitation happens, collection possibilities are basically limitless.
The surface is certainly hostile, but even 1960s Soviet technology was landing on it (also, contrary to popular myth, there is no acid at the surface; it's unstable at those temperatures, the sulfur inventory is only SO2 there). But in many ways, the surface is very gentle. Mars eats probes with its hard landings, but one Venera probe outright lost its parachute during descent and still landed intact, as the dense atmosphere slows one's fall. It's been calculated that with the right trajectory, a simple hollow titanium sphere launched from Earth could arrive at Venus, enter, descend and land all intact. Simple thermal inertia (insulation + a phase change material) can keep an object cool for a couple hours; with heat pumps, indefinitely (and yes, heat pumps and power sources for the surface conditions have been designed). Even humans could walk there with insulated hard suits, like atmospheric diving suits. Indeed, some of the first space suits NASA designed for the moon (ultimately ditched for weight reasons, despite the superior mobility performance) were similarly jointed hard-shell suits.
On Venus's surface, a lander or explorer can literally fly, via a compressible metal bellows balloon. Small wings / fins can allow for long glide ratios. Loose surface material can be dredged rather than requiring physical excavation, potentially with the same fan used for propulsion. Reversible ascent back to altitude can be done with phase change balloons - that is, at altitude, a lifting gas condenses and is collected in a valved container, and the craft can descend; at the surface, when one desires to rise, the valve is opened and the gas re-lofts the lander.
On Mars, you're stuck in one location. The problem is that all minerals aren't found in the same spot; different processes concentrate different minerals. And you can't exactly just get on a train to some other spot on the planet; long-distance travel requires rockets, and all their consumables. But on Venus the atmosphere superrotates every several days (rate depending on altitude and latitude), while latitude shifts in a floating habitat or lander can be done with minimal motor requirements. So vast swaths of the planet are available to you. Furthermore, Venus is far more dramatic in terms of natural enrichment processes; wide ranges of minerals are sublimated or eaten out of rocks and then recondensed elsewhere. Temperatures and pressures vary greatly between the highlands and lowlands as well. There even appear to be outright semiconductor frosts on parts of the planet. Lava flows show signs of long cooling times, which promotes fractionalization and pegmatites. Volcanism is common, primarily basaltic but also potentially secondary rhyolitic sources. A variety of unusual flows with no earth analogies (or only rare ones) show signs of existing, including the longest "river" channel in the solar system (Baltis Vallis). While there's no global tectonic activity, there appear to be areas of intense local buckling between microplates. The surface conditions of the planet also appear to have been very different at many times in the past. It's all a perfect setup for having diverse mineral enrichment processes. Yet there's almost no overburden (unlike Mars, which is covered in thick overburden on most of the planet).
As mentioned before, Venus has significantly superior orbital dynamics to Mars, due to the Oberth effect. Venus-Mars transfers are almost as fast and almost as low energy as Earth-Mars transfers. Venus-Earth transits are super-fast, esp. with extra delta-V added. The asteroid belt is, contrary to intuition, much more accessible from Venus than from Mars. Also, gravity assists are much more common around Venus - when we want to launch probes to the outer solar system, we generally start with sending them first inwards toward Venus, then back between Venus and Earth and outwards from there.
From a long term perspective, both Venus and Mars have problems with terraforming, with some things you can do "relatively easy", and some that require megascale engineering on scales best left to fantasy. You can boil off Mars's polar caps, but the amount of CO2 there is still quite limited, and there's just not that much nitrogen inventory on the planet (it's been lost to space), which also matters to plant cultivation. You could probably engineer active radiation shielding from orbit, maybe direct more light to the surface, but you can't increase the gravity. Etc.
With Venus, one of the earliest ideas for terraforming it was from Carl Sagan, before the planet was known well; he proposed seeding it with engineered bacteria to convert CO2 to graphite and release oxygen. He later rejected his idea, on the grounds that a high temperature surface of graphite and oxygen would be a bomb. Later studies showed that the timescales for said conversion would be tens of thousands to millions of years. But in a way, that is actually a savior to his idea, in that Venus's rocks contain unoxidized minerals. In analogy to the Great Oxygen Catastrophe on Earth that created our banded iron formations, slowly exposed to oxygen, Venus's rocks would weather and sequester the oxygen and deposited carbon. Hot, high-pressure high-oxygen conditions would never have a chance to exist.
Various faster methods have been proposed. A common one is that of the soletta, a thin orbital sunshade. Another is building an "alternative surface", aka propagating floating colonies to the point that they are the new surface - and indeed, below that surface, they could exclude sunlight to the below atmosphere. Regardless of the method, the cooler the atmosphere gets, the lower its pressure gets, to the point that you can start outright precipitating out the atmosphere out as icecaps.
Just like Mars will never have high gravity and probably never much nitrogen, Venus would probably never be fully Earthlike. It would have enough nitrogen that, barring loss to weathering, people would have a constant mild nitrogen narcosis, like always being ever so slightly tipsy. It would remain a desert planet, barring massive influxes of ice (which present their own challenges and problems), or of hydrogen (pre-cooling). But then again, the very concept of terraforming anything has always required one to put on thick rose-coloured glasses ;)
I don't say all this to diss on Mars. But our obsession with "surface conditions" has led us to ignore the fact that if you're going to the extremes of engineering an off-world habitat, having it be airborne is not that radical of an additional ask, esp. on a planet with such a big "fluffy" atmosphere as Venus. If Venus's atmosphere stopped at its Earthlike middle cloud layer, if there was a surface there, nobody would be talking about long-term habitation on Mars - the focus would have been entirely Venus. But we can still have habitats there. The habitat can, in whole or part, even potentially be its own reentry vehicle (ballute reentry), and certainly at least inflate and descend as a ballute (with a small supply of Earth-provided helium as a temporary lifting gas until an Earthlike atmosphere can be produced). Unlike with Mars entry, you're never going to be "off course", or "crash into something" because you got the location or altitude wrong.
(Getting back to orbit is certainly challenging from Venus - all that gravity that's good for your body has its downsides - but the TL/DR is, hybrid and/or air-augmented nuclear thermal rockets look by far to be the best option. Far less hydrogen needed than chemical rockets, far lighter relative to their deliverable payload, only a single stage needed, and in some designs have the ability to hover without consuming fuel. This is, of course, of great benefit for docking with a habitat, avoiding the need for descending rocket stages to deploy balloons and then to dock those to the habitat. The hydrogen and mass budgets involved are totally viable)
