I REALLY want there to be a better YT replacement on the fediverse or in some form of decentralized way.

As people are pointing out, videos are very large files, and therefore very expensive to host. The fediverse can mitigate this a little bit, as everyone can host their own videos on their own server, but that's not enough, and extremely inconvenient.

I do wonder if the blockchain/torrents can be used here... I'm not a dev or anything so IDK how any of it really works, but I think something to that tune is gonna be the only way, since traditional servers don't seem to be viable.