Discord as a platform works extremely well because all communication is very clearly within a context. And there are no exceptions.

Servers feel like physical clubs that you are members of. You meet people in clubs and get invited to other clubs. Everything is organic.

You can make your own club, but you also have DMs which is more like your own house. You can chat with someone in your house.

The fact that there are no exceptions to this system makes it comprehensible to the user.

nostr has difficulties with comprehensibility because it is full of exceptions and there is very little context that users can grok.