Not every user will be equipped to build, maintain or even run their own client/relay safely. These users will require either third party clients/relays as a service, or third party software they are not equipped to manage on their own.

That does not translate in a true p2p network. there is still a chance fewer such trustworthy projects will support most users. Where are they hosted? who maintains them?

true p2p is not feasible. there must be something in between.

on the other hand #nostr already allows for p2p networking when honest alternatives aren't available. p2p alone cannot scale.