On the touchscreen I can use pinch to zoom in browsers like Firefox and Microsoft Edge (I use it because Firefox doesn’t have PWA support), it is also supported in apps like Gnome Maps and Kirta. In Krita I can even move and turn the canvas with two finger input, it seems moving and turning are both supported in GNOME.
Outside of apps, you can also use a three finger up gesture to go to the active app overview. And you can switch between the active workspace with a three finger swipe to the right or the left (this can make switching between applications really fast). Long press for right click seems to work in most places.
You can drag an app to the left or the right of the screen to make it fill up half of the screen, and drag it to the top to make it full screen.
Yup YouTube makes it very easy to receive money from adds and people that have YouTube premium. Having a YouTube premium subscription means that you are at least supporting the creator of every video that you watch a little bit (from what I can find 55% of what you pay is going to the creators). Yes YouTube takes quite a large cut, but video hosting in high quality costs a lot of money.
I think it will be very hard to do this on a decentralised platform. People don’t trust just anyone with their money, so it could lead to people abandoning smaller servers and you can be sure that bad actors would pop up and try to abuse the system. And even if you do this the right way, you would have to build this system entirely before you can convince creators to move to this platform.
It will also be really hard to offer the same quality and reliability that YouTube offers, without taking a larger cut than the 45% that YouTube takes. Hosting a large video platform is expensive, and many of the Fediverse users are anti-adds and will run an add-blocker and maybe even sponsor-blocker.