Main issue with Nostr is similar to Mastodon problem, one who manages relay is similar to one who ones the instance on mstdn, oh change instance oh change relay, same thing, not easy, if you blocked from a main/big relays thats it, no point to have on 10 people relay
Discussion
I think Nostr has a chance to work in an authoritarian world and thats what matters, same as XMR.
If we look into lightning wallets they are custodial mostly which completely differentiates it from Monero's roots.
It could be more of a as popularly discussed, Visa or Mastercard for crypto/blockchain industry.
More developments in later years will show if its viable for what its created.