I think people forget that most social apps start as niche- for example when I checked out mastodon 3 years it was just a hand full of sub cultures.

nostr even now is also not really prime time ready- even if it is improving fast. So it's good that it has a dedicated user base already that tolerates the wonkyness while it is essentially in open beta.

I also think until relay switching/lists/topic curating improves its just physically difficult for the ecosystem to grow. Right now I manually check my favorite accounts and have no way to organise them- that is not sustainable for a bigger more diverse community. Tech is not there yet.