AWS requires a different email address per account yes. I don't see how it's bad? In your case, if you lost access to one gmail account with a dozen AWS account

AWS requires a different email address per account yes. I don't see how it's bad? In your case, if you lost access to one gmail account with a dozen AWS accounts attached to it, that would affect all your AWS accounts? Better to have them fully separated so they can't affect each other.