Mostly… self hosting also works and in the case of Git, I do not see any benefit for Nostr over self hosting as most projects have centralized leadership 

 what about discovery? 

 Discovery on Nostr is not a bad idea, though.

And identity. It would solve having to create an account for each instance. 

 but you still need to ssh on each instance  

 git over HTTP and NIP-93 or whatever it was 

 good idea, but then you have to accept anyone pushing stuff to your server? 

 you could do access control