I have said before, I'm personally not interested using "Something I have"/"device bound" as an authentication factor. I'm also not interested in the sync "workarounds" that store keys in the cloud.

People have replied it's possible to extract the private key, but it's not clear to me that that's usable (maybe it is I don't know). It's certainly not in line with what passkey devs want people to do and not do, so I'm not interested in "fighting" against the "flow" so to speak.

I'm happy with TOTP, as I can manage and use the codes where I want, under my control.