"eggs in one basket" is fiat thinking. Bitcoin is money. Nostr creates a fully censorship-resistant social network, which is now becoming monetisable.
Bitcoin, first of all, is not "one basket" it is over 10k servers. Nostr is also some thousands of servers now too.
Centralisation is vulnerable in the way you talk about but there is nothing centralised about Bitcoin. Bitcoin's whole purpose and primary defense against being shut down is precisely distributing risk by allowing anyone to run a node, and the same thing is happening with Nostr.