And pay to groom themselves.

I've never noticed a correlation between "amount of money" and "capability to groom and present self," positive or negative.

Sure, you have. Many professional cliques have unstated dress codes. The more rarefied the clique, the more expensive the outfits. Banking and venture capital come to mind. If you make it to the top you can wear what you want again.

I'm obviously talking about features which aren't attributable to the quality of the photo. Facial structure, symmetry, etc.

A good photographer can work wonders ;)

I did this. I went to a photographer who specializes in it. He booked a makeup artist, a hair person, and they took a few dozen shots at a couple different locations and with different outfits. The whole thing was half a day and like $500.

I look way better in my professional headshots than in reality.

So this tracks for my N of 1.