2FA is still available in the free tier, it’s just limited to TOTP and email code based 2FA. The paid teirs unlock additional methods like FIDO2 and yubikey protocols. Even if you don’t use the advanced 2FA methods or any of the other benefits, it’s still good to throw them a little money to keep them running.
If there’s one good thing that Back 4 Blood did, it’s remind me how good Left 4 Dead was, so I went and played that instead.