If you’re annoyed by those floaty prompts on websites to sign into them with your Google Account, you can turn them off for your Google account! Link: https://myaccount.google.com/u/0/permissions
@clairely_inexplicable@rmondello privacy.firstparty.isolate=true in Firefox. (Will effectively clear all cookies/state, after that stuff embedded in one site can't see cookies/sessions from where it was the top level site.)