GitHub sent you a letter? What does their letterhead look like? What'd they put for a return address? How much postage was on it? Seriously though, MFA may be

GitHub sent you a letter? What does their letterhead look like? What'd they put for a return address? How much postage was on it? Seriously though, MFA may be annoying, but that's nothing compared to a credential-stuffing hacker taking over your account. Spend a few bucks on a Yubico Yubikey. You'll be glad you did.