One thing that comes to mind is with the earlier WebAuthn implementations in iOS, before they were stored in iCloud and called passkeys, there was no management interface for stored passkeys and 'clear website data' (to delete cookies etc.) would actually erase all credentials permanently. It was useless this way.
I do not mean passkeys in general but early iOS implementation was useless since it deleted passkeys along with your cookies and other website data. The passkey iOS implementation is useful in its current form.
