As a PeerTube instance owner, I would say that not everyone needs to join a single instance (that would be the biggest mistake). Instead, if you can self-host one and invite people you like and know, they can provide quality content. Also, having multiple smaller instances makes it easier to moderate and have quality control. Federation and direct subscription to channels also improve instance discovery.

never give ai things you do not want to be public even if they let you opt out :)