First off you're making the mistake of equating ads with tracking. You do not need tracking for ads - context based advertising is widespread on YouTube already.
Secondly there's nothing special about these services except their moat. Even when serving video was a novel problem, there was dozens of competitors. Nowadays it's a solved problem. If they leave, they'll be replaced overnight, just like many other social networks, messengers, video platforms, etc. before them. They'll go far not to give up a position they will likely never claw back.
Secondly there's nothing special about these services except their moat. Even when serving video was a novel problem, there was dozens of competitors. Nowadays it's a solved problem. If they leave, they'll be replaced overnight, just like many other social networks, messengers, video platforms, etc. before them. They'll go far not to give up a position they will likely never claw back.