>In the Nostr case, every one of these relays would have to turn on you simultaneously for you to have a problem.

All the relays, or just the clients, which wouldn't take much if they automate hiding content based on reports, which most likely all clients will eventually have to do.

Most content is also centralized on a few relays so that wouldn't take much either, only reason it doesn't happen is bc databases are decoupled from the clients, so everyone just lets clients handle those decisions.

As with all decentralized systems, its resilience is mostly an illusion as is sustained more by the community than the architecture itself.