To your point, the amount of money/effort to even try and rival YouTube (and/or Google) would be a hell of a task for sure. Since you would want it to be open, well moderated (but not so much that the majority of people scream "censorship!"), and be able to store/encode/serve a wild amount of video daily. And the later 2 things get exponentially more difficult as you scale.
It would need to be like the Fediverse on steroids, doing a distributed filesystem allowing every federated member to host/encode/serve part of the burden (like Kazaa/Limewire/DC++) but in some manner that people could be assured node hosts couldn't tamper with videos. And then you would also need some sort of reward for creators that wouldn't somehow lead to greedy power struggles causing an implosion of your open platform.