This is a genuine question, even though I already know some of the biological answers that some might bring which is a symbol of protection and masculinity, I really cannot fathom the reason for women that vet men by putting out strict height requirements (e.g. if it doesn't start with a 6...)

is that I don't even need to be an expert in statistics to know that every time you put a certain immutable characteristic into play (e.g. Height), that would mean a large pool of men is already being cut off from the market, as you've already cut off 85.5% of men out of the equation. (US Men, 6ft+ is 14.5%) Meanwhile, I don't even need to take from FDS that women generally want men that are taller than herself, which is another variable to account for. This cuts off more men if she's above 6ft tall. Then there's another women that want their man to be at least xxx inch/cm taller than her, another limiting factor. If you're using a dating app to vet, some might lie about their height too but I'm not making it much of an issue here because it's already such a headache to count them.

Now all of that only ticks one box out of all the requirements that she wants, you have not completed all the other boxes to tick yet as there are much more factors such as: having game, your 'type' of personality, your 'type' of looks, certain income bracket (which also varies), age, car, family (kids/no kids), etc.but here's the thing, even if another dude has all/almost perfect criteria except height, he would already been disqualified in the beginning because of his height. Another issue is that, even if you found a man that checks all the boxes, what are the odds that he would like you back in the first place?

I would like to know how such vetting strategy manifest in modern day and age, for better or worse. inputs would be greatly appreciated.

Tl;DR Strict Height Requirements, Statistically handicapped against their own odds for maximizing outcomes