I grew up rurally, and tbh it was pretty hellish for me. Small schools meant I never had any real friends I had a proper connection with, instead I just sort of got stuck with people I didn't really have much to say to for over a decade. I never came across anyone who shared my interests, in fact I felt I had to hide a lot about myself because comparatively I was very weird. In a city or even a large town I wouldn't have been weird at all. It was terribly lonely. But even if I had made great friends, seeing them outside of school would have been an ordeal, so probably tough either way.
I'm not a particularly outdoorsy or sporty type, so a lot of the 'fun' to be had was my idea of a chore. I tried to get into it, but it's just not me. There was a ton of drinking, drugs and really dangerous behavior, an unusually large number of kids I knew or knew of died young in stupid accidents, or hurt themselves very badly in stupid accidents. Also a lot of suicide.
I'm a very independent person, so having to rely so much on my parents just to do basic things like, get out of the house, that really bothered me. I would have loved a part time job but the jobs weren't there, and again the logistics of getting to a job wouldn't have worked out anyway. I hated that going to see a movie or to a more interesting set of shops was a huge deal that required planning and parental help. Often by the time I'd gotten it all sorted it had been such an effort that a lot of the fun had been taken out of it anyway.
There was definitely a lack of opportunity. It took me longer than it would have otherwise to break into my chosen field, because 90% of the other people in it spent their late teenage years doing work experience and then internships and volunteering. They already had experience and connections, so we weren't on a level playing field at all. I only feel like I really caught up a few years ago.
I have teenage DC's now, and we live in the city. I'm almost jealous of all the things they get to experience. Any interest they have, they can pursue in some way or another. They sign up for classes outside of school, visit museums weekly, volunteer at various organizations. One of them just did an internship with their favourite writer, something that would have been unimaginable for me.They have lots of good friends they can go see with little effort. They're very independent, they have part-time jobs they love. Most of what they do is free or costs very little. On the rare occasion they blow all their cash and have nothing left, they still find tons to do. I think my eldest would have been ok in the country, but the others, definitely not.