I'm totally tech illiterate and don't really understand either protocol tbh lol. I'm a total casual idiot user.
Culturally I think bluesky and nostr do suffer from fairly strong embedded user groups. Nostr is obviously bitcointwitter rubbish -heavy and bluesky has a lot of LeftTwitter2010s vibes. Both can be quite repellent to users outside of those groups (by accident or on purpose, a bit of both maybe). Bluesky has sort of broken out somewhat.
I think it's a bit of a problem still for both, moreso perhaps nostr which is much smaller as a userbase and topic-breadth or something. They both do kind of have bad reputations outside of their bubbles, and can be unwelcoming in different ways.
I'm not sure how either succeed long-term tbh. Will be interesting to see, or what comes next. Or if it's just even more balkanised social media protocols lol ¯\_(ツ)_/¯
I believe one of the issues nostr people have with 'corporation bad' Bluesky, is that it is a central point failure maybe? How is bluesky sustainable? I have no idea tbh 🤔