As for any of these cases, we do receive legitimate emails that require being logged in, Google or otherwise The answer is simple: use your bookmarks/password

As for any of these cases, we do receive legitimate emails that require being logged in, Google or otherwise The answer is simple: use your bookmarks/password manager/... to login yourself with a URL you control in another tab and come back to the email to click it (and if it still asks for a login then, of course still don't do it)