I think it's too early to tell. What I will say is people talk about other stuff besides the fediverse on the fediverse, I can't say the same for Nostr. It's mostly super high noise: AI spam, boomer tier memes, obvious scams, and accounts with posts like "I just set up Nostr" and zero other activity.

I also think it's interesting that people here don't know what ActivityPub is. It suggests to me a lotta people haven't done the bare minimum research on alternative social media but are still posting hot takes about it.