I've also thought about something like that for reddid/lemmy through tags. Like you don't just up or downvote but you vote "funny", "serious" or "insightful" or "wrong" or "trashy" etc. So you can separate posts and comments about topics. Also things like tagging a post as "repost" should be done manually or mostly automatically through image search so you can still upvote without feeling duped. And once AI becomes smart enough in the future to reliably detect common lies and propaganda you could do more of it automatically.

But for youtube you'd mostly need a common "public" server network of storage and streaming servers with a common fediverse interface. And you'd need some kind of global and voluntary coop subscription where people can pay 5 bucks that is split and paid out to any content you watch. Then you wouldn't be dependent on advertising any more.

Anyway there are so many good things we could try but we won't.

I just want to have the ability to control the algorithm

I know of at least one selfhosted alternative: https://github.com/chris-lovejoy/YouTube-video-finder

There may be others if you look around.