The issue is that Nostr is competing with other channels I have to post stuff, same as with all other writers.
I can have the same interesting convo with the same people elsewhere. Nostr has to work to get me to write something publicly and take all the heat, so it has to add some value.

Npubs are taking the more interesting stuff off-Nostr to Telegram or SimpleX or whatever, or putting up walled gardens, and Nostr is stuck with the "post a picture of a pretty leaf" and "here is my software update" leftovers.