We can live with both.

If people say "nostr isn't decentralized" we can argue that this only applies to some clients, not others.

People who depend on large well-trafficked servers have their own set of problems that will eventually motivate them to change to something else. That something else might not be the gossip model, but it might be a different thing.  But I think they will eventually change because:

* Centralization isn't something users want due to censorship concerns, so users will vote with their feet by switching clients,
* Fixed relay lists mean people are unable to see all the notes from people they follow. Users don't want to depend on some possibly-flakey possibly-censorious middle-man relay or copying service, so users will vote with their feet again,
* Centralization will cause the central hubs to become overloaded in CPU, space and bandwidth terms (I don't know which will be the straw breaking the camel's back).

I don't like telling other people what to do. I prefer figuring out how to live with whatever they do.