If a relatively small number suck HUGELY at a skill then 80% may be better than average. (50% will be better than median.)
We probably should just avoid saying "average" and use "mean", "mode", "median", or whatever we actually mean instead.
It’s only when someone says something like the average family rather than saying the average income when things get ambiguous. Typical on the other hand is closer to mean because it’s tossing out outliers.
It is also pretty absurd to assume without explanation that a minority who are especially bad at management have even their minority presence in management given that if sucking matters it should correlate with some type of failure that eventually correlates to drop out.