How to get Youtube on mobile without ads and to play in the background without a premium subscription

I can't belive I never thought of this, it's so supprisingly simple:

1. Get a browser that allows you to run addons (e.g. Firefox).
   

2. Get an adblocker extension (I use uBlock origin).
   (2.1. There was an issue with uBlock and Youtube a videos a while back: If the videos don't load, go to uBlock settings and remove the "quick fixes" filter list. Hit refresh and it should load properly now.)

3. Browse Youtube through adblocked browser and enjoy without ads.

4. To play things in the background, switch to any other app (or desktop). Then hit play in the notifications menu. Same works with a locked screen.

I suggest switching the app first before locking the screen, because somehow it plays more reliably.
In any case, it pauses playing every 30min to 2h. I think it has something to do with the "Are you still there?" detection that you'd also experience on a desktop.