People's internet connections are already straining to stream 1080p video. And even so, the quality of existing 1080p streams is mediocre; visual artifacts are often easy to spot. It is possible to get better looking 1080p video by using more bits; broadcast HD and Blu-Ray both do that. Blu-Ray and streams are mostly encoded with H.264; broadcast digital TV in the US is at a disadvantage because it uses MPEG-2 but it uses enough bits to more than overcome the disadvantage relative to streamed video.
4K ups the ante. For a given level of freedom from artifacts you need about four times as many bits; the exact ratio depends on the content and how well it compresses. The majority of home internet connections aren't up to the challenge of carrying even one 4K stream, let alone multiple streams as you might have in a family or a group household; nor is the rest of the infrastructure of a typical ISP. Using a better codec decreases the number of bits that need to be sent.
And 4K is not the end point. That level of resolution may be adequate for content that you only view at a typical screen distance (as we look at a movie screen, TV set, or computer monitor), but more immersive forms of video such as video walls, where we might look closely at a small part of the picture, will require even higher levels of resolution.
It's not so much that the OS needs huge amounts of memory. It's that the apps do, and that amount keeps increasing over time. The resident size of the current Facebook app on Android, for example, is over 100MB, and since it checks frequently for updates it can't be effectively suspended and thrown out of RAM. Some of Google's own apps, notably the Chrome browser, are also culprits.
iOS doesn't need as much RAM because it's not a full-bore multitasking OS. It does limited background operations, and the scope of those has increased over time, but still stops short of the full thing. That means that iOS doesn't need to have as many apps resident in RAM. Android can also suspend things to disk if necessary, but that tends to mess with the expectation that you can switch instantly to another app. Chrome can also minimize its memory use if the device is running low on RAM; mostly it does that by discarding tabs other than the currently selected one, with the consequence that switching to other tabs is slower because they may have to be rerendered or even downloaded again.
Sounds like you don't commute by public transit and walking.
If you travel everywhere by car and just carry the laptop at the end points, weight isn't that big an issue. If you go everywhere by public transit and walking, it matters more because you're going to spend a lot more time actually carrying that laptop. It's not unusual to be looking at a mile walk at the end point.
Weight also matters to frequent flyers. First, you may be carrying that laptop for a while; in larger airports the walk to your gate can be significant, and if you are doing transfers for international travel you can face a LOT of walking. (Philadelphia, I'm looking at you.) Second, airlines are cutting back on the permitted weight of carry-on bags, and a heavy laptop might leave you without much weight to spare for the other things you need to take with you.
No, the result would be that the artists would get less money.
The artist payments from streaming services are calculated based on the actual revenue collected by the company. If Apple did this shell game, the artist share would only be 70% (or whatever their actual percentage is) of $7 rather than 70% of $10. The norm for other services has been that no royalties at all have been paid for listening during trial periods, because 70% of $0 is $0. Apple was forced to cave and pay royalties for their trial period because of its unusual length (competing services offer much shorter trial periods) and the expectation that a large number of users would sign up for it.
Spotify is different because its free listening tier is ad-supported rather than a free trial of the full service. It has two separate payment pools; one for subscribers and another for ad-supported free listeners. The subscriber plays currently pay artists about 10 times as much as the ad-supported plays. That can change depending on how successful the company is at selling ads.
The root of the complaint is that Apple is giving itself a competitive revenue advantage in this market. If an iOS user buys an Apple Music subscription, Apple gets $10. If that user buys a subscription to another service through an iOS app, Apple gets $3 and the subscription provider gets $7 - EVERY MONTH. The margins in streaming music are small, so giving all that money to somebody else hurts the streaming companies. (It also hurts the artists because of the way streaming payments to artists are calculated; the artist share is now 70% of $7 rather than 70% of $10.) The other services can sell subscriptions through other channels, in which case Apple doesn't get any money, but Apple won't let them promote those other channels in the app.
A reasonable compromise might be to allow Apple to get their 30% once. The app would take your first month's fee (with Apple getting a cut), but after that it would redirect users to the service's web site to buy an ongoing subscription.
Music from artist A and music from artist B are not the same product. But streaming artist A from Apple, Google, Microsoft, Spotify, Rhapsody, Tidal, Deezer, etc. pretty much are the same product. The purchasing process and the provided applications vary but the end result is the same, artist A comes out of your speakers.
Uber drivers are not paid under the table. If you drive for Uber, all of your rides are paid for by credit card, collected by the company, and dispersed to the drivers. Uber files a 1099 for all those payments, so the IRS knows about them. It is then the driver's responsibility to pay taxes on them.
Uber drivers sometimes receive cash tips, though not nearly as often as regular taxi drivers do. There is not currently any way to pay tips though the app; drivers are allowed to accept cash tips but prohibited from soliciting them. That income may or may not get reported to the IRS, depending on the actions of the driver. That is also true of any cash tips that you give to regular taxi drivers.