Quite often to get home from an unfamiliar place I just find a bus stop, see which buses run there and where they go (looking for major interchanges on the route, e.g. "I need a cross-harbour route - any of the about 80 such routes will do"), and go from there. Works quite well.
Doesn't work very well in this city... but I imagine that HK has a much better transit system than Ottawa, Canada. Here, to get from, say, downtown to, say, a shopping mall like Billings Bridge, there's essentially 4 routes. Sounds like a lot. But which route you take has a *huge* impact on how quickly you'll get there. There's 3 direct routes, and one involving a transfer. We'll skip the transfer one, because it follows the exact same route as one of the direct routes, just means taking a bus that doesn't go all the way and changing to a different commuter route.
That leaves the #97, which follows a bus-only highway almost all of the way, and then local roads. On a map it's a roundabout route, but it's the fastest because it's on the transitway.
The #1 is a direct route. Single road, no turns, straight line to the mall in question. Also quite slow, because it goes through three major commercial districts with a lot of pedestrian traffic.
The #8 wends its way through a residential area and takes twice as long as the #97 to get there.
If you're just using an app to look at which routes will get you to the destination, you may think that any of the above will work well. But when you actually look into it, the choice of which one you want to take is clear.
For the record, I mix both driving and transit. I take transit for my commute to work, because I don't feel like paying $200/mo for a parking pass when a bus pass is $100/mo and taking the bus is faster than driving during rush hour (because of the transitway I mentioned). But during off-peak hours or weekends, I will drive. As a result, I've needed to learn familiarity with the roads and general layout of the city, but also have a basic understanding of how to get around by bus. I do have apps for both navigation by car and by bus, but try not to rely on them -- sometimes either of them will muck up the directions and tell me to take a route that's longer than an alternative.