Well, for one, if you don’t want something stolen then you shouldn’t put it on your front lawn for everyone to take. There are plenty of services that require payment before you get access.
Two, they are essentially stealing our private data and selling it without our permission, so ads aren’t the only source of payment.
At no point was I informed by youtube that watching ads was a requirement for service. In fact until just now YouTube necessary even told be that using an ad- blocker was not allowed. Technically this is not the same thing. Otherwise I would be stealing every time I left the room when an ad was playing.