I think there is a nuanced but discernible difference between people who are talented and time constrained, and those who are mediocre/lazy/disinterested.

I used to think the incentive structure was a dominant factor, but my opinion on that has shifted over the past ten years. I think companies need to incentivize capable employees to stay, because they will often have many other opportunities elsewhere. But in most cases I don’t think those incentives cause people to work harder or more effectively than they would otherwise.