As someone who was heavily involved in P2P space, it is really hard to make P2P protocols and clients with decent UX especially on mobile. There's a whole host of challenges around discovery, network traversal, replication and connectivity that are real puzzles.

Yes it is ultimately the resiliency we need going forwards but it is really hard to do. It's worth playing with Secure Scuttlebutt, DAT/hypercore, Briar and others (even Bitorrent) to experience what the current state of the tech is.

One thing I would like to learn more about is whether there can be a Fedi server that's so lightweight that it can run in the client making it easily P2P. Doing that on mobile (especially iOS) sounds incredibly challenging.