Aesthetics and societal factors probably factor into this because I find that Americans in particular are absolutely obsessed with height. Yes, it's a factor in the beauty standard of most cultures, but it feels like no other Western country has as much staked on a person's height alone. Whenever I see posts about needing to hit a certain height barrier to be worthwhile, or people openly expressing disdain for short people, or idolizing being tall, you can almost guarantee the poster is from the US.

This is just my own observation, so it's probably biased. But if this correlation is real, that shows this is not just evolution. Subjectively, it feels like there's a lot of societal influence stacked on top of whatever is there initially.