Depends on what exactly you mean with "self-hosting". As in you can run your own dedicated servers across the world, with one or more providers, and run all the software yourself, have your own CDN. Varnish works great for that. If you're limited to "self-hosting as in hosted in my home" then yeah it gets harder. Maybe P2P/P2P-like thing could help if you're dealing with public content, like PeerTube?
So it remains an unsolved problem for self-hosting.
Depends on what exactly you mean with "self-hosting". As in you can run your own dedicated servers across the world, with one or more providers, and run all the software yourself, have your own CDN. Varnish works great for that. If you're limited to "self-hosting as in hosted in my home" then yeah it gets harder. Maybe P2P/P2P-like thing could help if you're dealing with public content, like PeerTube?