Stuff like individuous is better positioned to start mixing youtube content with videos from decentralized hosting. But I don't think anyone has committed to doing that. I'm sure google would not like it either. I know Freetube has already committed to not being interested in this. I'll be on the lookout for a fork.
But indeed Video is a different (heavier) beast than text. I would assume a less perverse set of incentives that a federated platform offers would get rid of 99+% of the "content" that Youtube currently hosts, but the remaining 1% would still generate traffic many times bigger than mastodon I'd think.
Peertube also allows to proeminently display a configurable "support" button to redirect viewers to your patreon/liberapay/paypal or whatever.
The only reason to not mirror your content to peertube? Because you want people to watch Youtube ads.
But, as this news show us, nobody want to watch the ads.
PS: I’m surprized peertube is not more famous so I posted it independently here: https://news.ycombinator.com/item?id=37906699