UI/UX and marketing are underrated in the FLOSS world in general.
Discussion
Because the biggest accounts were extremely early adopters. They know their favorite devs personally and don't care about new ones, and they are inured to poor quality.
Nostr specifically. Agree that it's a general problem, that has been keeping open-source from gaining market share.
Small teams. Most of them are backend technical smart people.
Generally smart people don’t know how to communicate with the rest. Unless they try really really hard.