Passkeys were hot last year, don’t seem to be catching on, here’s one view of why that is. Dark and sobering but convincing: https://fy.blackhats.net.au/blog/2024-04-26-passkeys-a-shattered-dream/
Passkeys: A Shattered Dream

Firstyear's blog

@timbray ah, I have looked at passkeys a couple of times and feared them because of lock-in, and this suggests that I'm not the only one thinking it!
@sil @timbray Lock in? Every OS supports them
@objc @timbray as far as I can tell, though, I can't move *between* OSes. If I set up my current phone as holding my passkeys, and then I change to a different phone (OS), I am just flat-out stuck; I cannot export my passkeys, or store them myself in some neutral format, or export them to a different device. I might be wrong on this, but every time I've asked I've got that answer, or no answer. If that's changed then I'll be happy to look again.

@sil
And of course, this post gets no replies... ( Well now it has one reply but still no answers)

@objc @timbray