Targeting single sites seems futile. Make Nostr into an equal to SSO like the Facebook, Google & Apple links to login every site has.
But what do people like my mom (who constantly needs to reset passwords) do when they inevitably lose their keys?
Discussion
Nostr: control your identity with one key pair, easily switch from app to app. Your data is yours only.
Also Nostr: if your keys get compromised or lost, that data is out of access forever. Just start again from scratch with a new pair.
I think the second point gets hand waved away too easily. For a large part of the population this is a major show stopper. Losing your entire online presence with no way of recovery would be devastating for people, and that needs to be solved. If a site has a solution where users can recover from lost or forgotten passwords, what does Nostr offer in that regard?