Yeah don't get me wrong, I wasn't disagreeing. I think the lack of interoperability is a major risk to adoption, but I also understand why we don't have interoperability today and why we likely never will.
What I'd like to see password manager vendors like you do, though, is to push FIDO and the OS vendors to have richer APIs for interacting with the hardware components that can back keys. To be clear, I don't want to use Bulwark to manage or export passkeys in my iCloud Keychain (I'm confident that will never happen), but I want Bulwark to be able to create a passkey that is backed by a secure element in Mac OS, and then be able request a wrapped version of that key to be exported, and later imported into a TPM running on a Windows OS.
What I'd like to see password manager vendors like you do, though, is to push FIDO and the OS vendors to have richer APIs for interacting with the hardware components that can back keys. To be clear, I don't want to use Bulwark to manage or export passkeys in my iCloud Keychain (I'm confident that will never happen), but I want Bulwark to be able to create a passkey that is backed by a secure element in Mac OS, and then be able request a wrapped version of that key to be exported, and later imported into a TPM running on a Windows OS.