Vast, persistent differences in competence across programmers are definitely real. Working in a homogeneous team for a long time can obscure it, sure. But if you can't think of any colleagues drastically better than you are, then either your work is on par with the giants of our field, or it's time to find some different colleagues who can challenge you and help you to continue growing. (Or you're making a conscious decision to rest, which is fine, but not while denying the possibility of alternatives).

I don't think absence of mistakes is what makes these people great, though, more like the difficulty of the problems they're able to solve, the effectiveness with which they can manipulate and discuss ideas, and the fitness-for-purpose of their solutions.