If you read the links, this includes their server clusters and employees across the entire world all doing complex load balancing and maintenance.
Sure, and none of that is necessary with a proper P2P system. If I’m torrenting something, it’ll naturally pull from seeders near me over seeders on the other side of the planet, so load balancing happens by every client being greedy.
The complex load balancing is only necessary because it’s a centralized service.
This protocol already exists and so does the system, PeerTube.
Why no significant quantity of people use it is apparent after you try it for a while; the entire server system cannot handle the commensurate volume of content and interactions that YouTube is popular for.
I thought PeerTube’s problem was largely federation (need to know which servers to use), which results in making it hard to find content to watch and probably has something to do with how load balancing works (i.e. are you mostly streaming from your instance?). I think Lemmy has a similar problem, but it’s at least pretty fast because text and images are a lot easier to manage than video.