I’ve been in charge of a 3rd party authenticator passkey implementation twice and both times the platform (be that chrome or apple) unfairly leveraged their position to push their solution above 3rd party options. Apple, in its most recent update, finally allows the user to disable iCloud keychain so it’s not an option always getting in their way if they use something else like 1pass or bitwarden. Chrome still puts themselves first before allowing the user to see the list of “other” authenticators to use, which isn’t serviceable as an other.