This question is framed to preclude the answer.
The real competitor won't be a video hosting service, it will be a content monetization model competitive to advertising. Even content monetization is a weak way of thinking about it, because by abstracting it from the people who want a certain kind of content, you've pre-defined your solution as just another tech without a clear market (a non-product).
The question of "I have all these videos, how do I sell them?" is completely different from, "How do I sell videos?" or "What will these people really pay for and how does video distribution get it to them?"
The question isn't how to reinvent streaming, it's how to discover something someone will pay for. Youtube's product isn't content, their product is the distribution it provides to people who make it - and a combination of the data and channel it provides to advertisers. That's what they sell.
So, do you really want to make another product for advertisers? Even if you really like advertisers and did, investing in another video streaming platform seems like the least smart way to do that right now.
The next real competitor to youtube will look more like AppleTV than Rumble. Arguably, if I will pay $15.99 for a season of Ancient Aliens, I'll pay $7.99 for all of 3blue1brown. It's a different monetization model, and that's the real competition.
If I wanted to make a video streaming product, I would pop up a level and find a market then determine whether their need was more for produced content, or for distribution, and then solve for the economics of that desire. The quesiton isn't how do I monetize this landfill of content, the real question is, who is this customer and what do they want?
I've thought some of this through, and reach out via my profile if you are with a company that is serious about this.