Actually noted a similar idea. Specifically want to emphasize social robustness, or how well individuals can share the same space.
Considering we're already decently robust to censorship, I don't see as it productive to worry about censorship unless you're specifically mentioning changes to the core of nostr. So I'm pro nostr-fragmentation.
From a historical perspective, we've typically never had this frequent contact with more people outside our tribe, and the times we did was less likely to be a positive reason. (probably)
Also thinking about something i'm calling a shield, or "on demand social bubbles". Bottom-up user defined communities.
Something as simple as a whitelist of npubs that you see and blackout everyone else, define multiple communties and there might be some interesting interplay between the overlapping npubs between users.