Complexity to new users is definitely not better on nostr, just as confusing if not worse, currently. The reason I think nostr is on a better track than AP, is because I came to AP running from problems that I had on reddit, only to find the same problems on a smaller scale. Here’s what I can think of off the top of my head:
Variety of clientes
Both AP and nostr fix this.
Centralised power
Nostr fixes this, by making it so that your identity is usable anywhere.
AP kinda fixes this, but doesn’t go far enough. If the admin of your instance decides to not federate with another instance, you have no say in that. Your only option is to migrate to another instance, and since AP doesn’t have nomadic identities, you have to start from scratch. Mastodon’s export feature doesn’t go far enough.
Disagreement with mods
Nostr fixes this by offloading modding to individual users. You chose to mute what you dont want to see. A highly requested feature here on Lemmy.
AP kinda fixes this, where if you don’t agree with mods, you can start a different community, or a similar community on a different instance, but then you have the same problem as with centralised power, and are at the mercy of admins.
To be truly sovereign on AP, you gotta run your own instance, which is very impractical, and lacks nomadic identities. With nostr, you own your identity, because your identity is just a cryptographic key, which can be used anywhere, on any node.
To be clear, I think AP is a clear improvement over centralised services, thus why I still use it. I won’t let the perfect be the enemy of the good. I just think nostr is the better protocol to build decentralised services on top of.