The first of my two biggest favorite features of Friendica over the other fediverse options are the post/comments idiom, more of a Facebook-like UX, over the status streams, the Twitter-like UX. The second is how much more pervasively it integrates with federated networks in general. It isn't just the ActivityPub fediverse that Mastodon, PixelFed, PeerTube, etc. rides on. It is also the entire Diaspora federated network, RSS's, and even networks like Bluesky (albeit using the client API not the ATProto federation system). It basically makes Friendica the hub of my whole social media experience.