Averages can be misleading. In cancer, it’s the outliers that matter. The average virulence of the cancer cells is less important that the few cells that are really bad.
Here’s an example of averages being misleading in terms of evolutionary success. If hens have very particular tastes, the rooster who appeals on average may not have as much success as the rooster who appeals to a niche. The high average is a generalist strategy. It’s OK for all the hens. That strategy can lose out to the specialists. If there are enough specialists, or if hens only make eggs with really attractive roosters, the generalist will not do as well.
So, bottom line, it’s dangerous to rely too much on averages. It’s true in business, too. A product that appeals to everyone can get out-competed by all of the niche products in a crowded market. There are a lot of flavors of pasta sauce. The sum of Ragu’s different flavors out-sell the classic Prego by a fair margin.