There are a few options and none of them are great.
First we have to split between paying for content and paying for the delivery.
There is already a platform where people pay for the delivery by letting their device be part of the delivery system. That’s Bittorrent. You can download by uploading. I don’t see why something like the Bittorrent protocol couldn’t be adapted to a Youtube like platform. And if the platform only serves a frotend that helps you find the correct torrent and then streams the content in a video player, the demands on the server would be low enough that it could be run using ddonations or something like that. It would basically be a legal version of the Pirate Bay.
For content creation on the other side, that’s a whole different can of worms. Content creation takes much more money. I see only two alternatives to ads, sponsorships and direct payments: government-sponsored content and unpaid content.
Government-sponsored content like e.g. BBC stuff is good, but it doessn"t nearly fill every niche that Youtubers etc. currently cover.
Unpaid content could work for some media, e.g. there are a lot of great books or music made by hobbyists without commercial aspirations, but making high-production-value videos without propper funding is just not going to happen at scale.
So all in all, I don’t see a future where we aren’t going to pay for content in any way.
Yeah, when you talk about ideal, home computers will not win. When you talk about an industry that overprovisions servers by ~50% and doesn’t even turn these overprovisioned servers off when they don’t need them, an industry that lobbies against any push to force them to put solar on their roofs, that lobbies against mandatory haste heat reuse and all that, I believe that a network of home computers will not be much more wasteful. Especially considering that the PCs are ildeing already anyway.
The problem with government-sponsored is, that we have to pay for it anyway. Unless you live in the Emirates, governments usually don’t have a money surplus and they need to make money through taxes. So wheter you pay through taxes or through direct contributions, there isn’t too much of a difference there.