I grew up in a small city of around 150,000 people. It was the kind of place where people settled down young and 'dating' didn't really happen beyond age 21-22 or so as the vast majority of women were taken by then. Pretty much all the guys I know back home who didn't shack up with a woman when they were in their early 20s are practically forever alone at this point and have been single and dateless for years.

The city also has a military base and a STEM focussed university, meaning there's a shitload of dudes everywhere you go, so competition is fierce. There's also a massive gym culture among guys there, pretty much all guys have a gym membership and many take steroids, something which seems rare where I live now.

Anyway, I lived in my hometown until I was 22, and after breaking up with my girlfriend at 19, I had a 3 year dry spell until I moved away, and began to think that my future either involved either being alone forever or a mail order bride (the latter seems to be super common where I'm from). Think I had two dates in that whole time, both women were obese and not very attractive.

Now I'm living in a much bigger city, in a neighbourhood with a lot of single people in their 20s and 30s, and in the last 4 years since moving I haven't had a dry spell of more than 3 months. I've slept with probably 15 mostly conventially attractive women in that time, most of those in the last 18 months since I broke up with my ex. Mostly from dating apps, but a couple from bars etc too.

TL;DR...I think a decent number of guys struggling are 'location-cels', partially based on my experience and the experience of other guys from my hometown who've since moved to bigger places. Obviously a 5'2 balding Indian janitor or whatever would struggle anywhere, but for average guys struggling in smaller, more rural places, moving to a large city could change their chances considerably.