What's wrong with PeerTube (aside from it being niche, but that's not really a problem per se, more an opportunity)? Is it difficult to deploy (again, an opportunity to create an easier deployment experience)?

I think economic sustainability of content creation is orthogonal to the hosting problem. Crowdfunding, like you say, could work, independently of the platform. I see lots of YouTube channels I follow use Patreon, for example.