Passkey lock in appears to be a temporary issue. One of the WWDC announcements was that the FIDO alliance worked out a way to securely port passkeys between platforms. I expect Google to adopt import and export before year end.

I believe the issue Google is attempting to solve is frustration when a single web page spams multiple permissions requests. (Location, camera, microphone, advertiser tracking, notifications, privacy policy agreements, terms of service, etc…). The benefit to Google is better fingerprinting when a single sheet allows all at once.

Edit: perhaps they will sneak in a Google automatic login as a permission to smooth user interactions.