As I understand things, a new nostr could be built from the ground up to overcome the particular reasons for the current nostr failing (if this were to occur).

However, given the unique ‘story’ of Bitcoin thus far, this would be almost impossible to replicate or closely match (if Bitcoin were to fail).

Therefore - from this angle of recovering from failure - I think that Bitcoin is more important than Nostr. 

 Makes sense, Bitcoin is a zero to one invention that can’t be replicated.. that a huge advancement for mankind