That's my impression too. It's not that good programmers are immensely more productive than decent programmers, it's that bad programmers are very bad. Not only can they just not do certain things, but they leave messes that others have to spend time fixing.

I've had days where I've ended up doing literally nothing, but still objectively outperform some colleagues because they rammed some shitty unstable undocumented race-condition hack into the codebase.