There's an article about the US Air Force and the "average pilot" https://www.thestar.com/news/insight/2016/01/16/when-us-air-...
The gist of it is: The average pilot doesn't exists.
I'd assume it's not much different with clothing. While the length for instance may fit, the shape of a sleeve or trouser leg may prevent you from wearing it comfortably. You'd need a insane amount of measurement from each part of the body.
That being said, I do feel like the clothing industry could be doing better than they currently are.