If companies still allowed you to login via password then any benefit you get from Passkeys would be null and void. In order to implement passkeys properly you have to disable password authentication.
The thing is it’s then on you to secure your passkey with biometrics or a password or whatever you prefer. Your phone most likely will use biometrics by default. If you’re on Mac or PC you’ll need to buy a thumbprint scanner or use camera-based window hello / secure enclave