There is a revisionist idea that Web 2.0 created walled gardens because (insert your least favourite thing) is evil, in reality walled gardens are just well scoped well aligned group of people with incentives to cooperate for the purpose of good experience.

The only other sustainable form of interoperability are;

1. Open source Dictatorship (Linux, Git, etc..)

2. Standards committees plutocracy (even worse than #1)

3. Adversarial interoperability; where you reverse engineer your competitors formats to steal their edge (.PSD, etc..)

#1 and #3 are the source of all the good things in the web.

If you want to change thing about Nostr, just build the best app you want, capture as much of the user base as you can, and everyone will just follow you, and you will save yourself the drama.