Using lemmy as example, when i request posts from another server, my server will request only those posts. It won’t request everything. Do you see the difference? That’s just how activitypub works because the alternative would be too costly. But you could design a federation system that replicates everything. A precise description is: Usenet is a distributed system where servers peer with each other to replicate articles (P2P at the server layer), while users interact in a client–server manner with their chosen news provider. Even your perplexity output admits that it’s not fully P2P like bittorrent. And if we count “partial P2P”, then activitypub would also count since even selective replication, is some amount of replication, and tbus “partial P2P”