If an app has a billion users, how many do you expect will delete their passkey for no reason? Is this more important then end-to-end encryption for everyone?
If deleting one's passkey for no reason was a thing, I'd expect a real story about a real user, rather then a made-up scenario.
The essay has a condescending attitude towards the normie computer user who can't possibly be expected to know, but it's precisely the normie computer user who would never get the stupid idea of "cleaning up" their passkeys in the first place -- that's something only a nerd with a neurotic attitude to their computer would do.