What are you talking about? I can literally export all that data to another OS or password manager. Takes a whopping single click.
I didn't realize this was supported, I'm kind of favoring Apple's Passwords app since you can lockdown your account and they are very on top of someone accessing anything of yours. Any time I power on an iPad I havent used for months they tell me a new device can read my texts type of thing, which is a nice paper trail.
Only to other proprietary systems within the FIDO Alliance that you don't own or control.
Additionally passkeys allow services to detect and ban specific password managers, so have fun when the only approved managers that works consistently across all services are Google/Apple/Microsoft. There is already a list of "bad" clients here https://passkeys.dev/docs/reference/known-issues/