Most people will though, because they’re either in the Android or Apple ecosystems.

Yeah but only being about to login to something if you’re on a certain ecosystem is horrible lock in. It’s why I always choose email sign in over Apple.

The standard has portability mechanisms, both for ad hoc authentication across ecosystems (I logged into login.gov yesterday on Chrome browser using my iPhone passkey) as well as exporting passkeys to ecosystem independent vaulting systems.

It makes sense to approach this new paradigm with a healthy dose of skepticism, but there is evidence your concerns have solutions.

Firefox should have a platform entitlement that lets them just delegate to Apple's implementation when available. This is I believe what they do on Windows.

I think they need to be in the App Store for this and I’m not sure why they aren’t.