The only instance I know of that is best suited for that use is peertube.wtf, who the operator of also happens to be semi active here on lemmy too.

You can add channels from other instances on any peertube instance as long as they are federating with them but the issue is that there are not many peertube instances that aren’t just super focused on a certain thing and so this tends to kill the interoperability more than help it, which is why I think peertube.wtf is good for casual youtube-like use because it is federating with all of them, its difficult to do because videos are expensive to store and share so it will be slow to improve but steady to grow just like the rest of the fediverse.