I do agree that 99% of users don't want to run infrastructure. I think there's a difference between Fediverse-style federation/decentralisation and true P2P/Bi

I do agree that 99% of users don't want to run infrastructure. I think there's a difference between Fediverse-style federation/decentralisation and true P2P/BitTorrent-esque dectralisation. BitTorrent, in its current iteration, does have many semi-technical users, but perhaps your grandparents would struggle to use it. I think a much more friendly UX could be built; maintaining its decentralised properties would be more difficult but not inconceivably so. I actually think transparent decentralisation is possible but the current policy settings (copyright, surveillance and advertising) somewhat disincentivise people from working on it, to the extent that most of the current projects are hobbies, crowdsourced or funded by research grants.