I have a hard time imaging a free, open video hosting service will ever succeed. YouTube's infrastructure is insane, and that's reflected in their costs.

Any sustainable video hosting platform is going to need a solid monetization plan because the costs of hosting and streaming exabytes of video is just not sustainable on donations. Platforms like Floatplane or Nebula seem like good alternatives, but they've chosen for a subscription-only model - which I personally think is the fairest solution.