How do I remove all Apple ID security keys?

From About Security Keys for Apple ID - Apple Support

"To stop using security keys: Open System Settings, click your name, then click Password & Security. Click Security Keys, then click Remove All Security Keys. If you remove all security keys, your Apple ID reverts to using the six-digit verification code for two-factor authentication."

This is a horrible feature and needs to be addressed by Apple. Using an iPhone and a passcode a thief can remove your security keys with a few clicks. You can have a 30 character password you never wrote down, a security key in your vault, and anyone with the passcode can lock you out of your entire Apple ecosystem with a few clicks.