Let me start by saying you do what you want to do. Wanna live in a city? Do it. Out in the country? Do it. An isolated island in the Pacific? Do it. I'm not telling you what to do. Find your own way.
That said, I think a lot of what's being said ITT has to do with the age of the posters. When you're young, you wanna be with other humans. We're social animals. But there comes a time in most people's lives when you wanna be sleeping by 9:00 or 10:00 at night. You wanna be up and around in the daytime. And you begin to value space. Elbow room. Might happen as early as 35 or as late as 60, but it'll probably happen. You'll get sick of the crime. The trash. The urine smell of the streets. And your view of the millions of fellow city dwellers will be less flattering. You'll see that many of them are cold, soulless, and just concerned about themselves. You'll begin to ask yourself, "Why do I like being here again?" Not EVERYONE goes through it exactly like this, but enough do. But if you like the city until you're 99, more power to you!