I’ve come to believe that there are two components to performace: awareness and ability. In general, they both have to improve before someone improves their performance.
It is possible to have a deep imbalance between the two. We call people with way more awareness than ability “critics” and people with way more ability than awareness “naturals”.
I suspect that it is difficult to improve with such an imbalance, though, and that many times people who have plateaus are actually in the process of growing their awareness faster than their ability.