As a follow up to the post linked below, I agree and feel at the very least this should be an option.
If we link another login account, Google/Apple, give us the option to disable Plex account login. The main purpose of this implementation, to me, is for the added security. If my Plex account login is still enabled, and without MFA available, there is no inherent security benefit in linking said accounts.
For myself, I don’t recall the options being available to signup with a Google account at the time of creation of my account.