There is no way the fediverse will replace youtube.
Youtube Is very expensive to host, and the proof is that there is no actual competitor to it.
Right, except we aren’t trying to “replace” youtube. Those who are prepared to put up with youtube can have it. Same with spez/reddit. If people like those platforms, and happy with them then they can stay there. Those of us who don’t care for them can develop communities and content elsewhere.
If you’re cool with algorithms showing you ads every five minutes then by all means stick with the commercial platforms, but you’re also generally welcome to help build or support a platform that provides a better user experience – and doesn’t use revenue growth as the primary motivator for everything.