If your only exposure to passkeys is through their Android and iOS implementations, I could understand this initial reaction, but they don't only exist on Andro

If your only exposure to passkeys is through their Android and iOS implementations, I could understand this initial reaction, but they don't only exist on Android and iOS. It's entirely possible to use passkeys outside of either platform by using any FIDO2 security key with discoverable key storage. There are even existing open source apps that emulate FIDO2 security keys that you can use. I also believe that passkeys can be backed up and exported on Android/iOS, either now or sometime in the future. The FIDO Alliance is working on standardizing the backup and transfer of passkeys so that they can be exported and used however you see fit. That said, I don't use the Android or iOS implementation of passkeys and probably never will. It's possible to use passkeys without ever giving closed platforms the keys to your castle.