The first point I would like to make is that country life may look boring, as you spend all your life with the same people as there really few schools, universities, places to work in so you have to tolerate everyone whether you like them or not. There also arent many other ways to entertain yourself more than playing sports, going to the park and hanging out with your friends. Even if doing these probably wouldnt be fun after the tenth time, it is much healthier than staying home all day surfing the internet and funnier than playing video games without talking to each other when you invite friends over like city people. In addittion, country people are much more friendlier as everyone knows each other, which can be useful if you need any kind of help.
On the other hand, more people live in the city, that means that you can meet new people every day, which makes your life a little more exciting, no matter how monotonous it can be because of your job. But even if you think your job is always the same, there are lots of other opportunities in the city that you wont find boring, and it probably wont take more than 30 minutes to arrive as everything is blocks away, unlike in the countryside.
In my opinion, even though there are all kinds of pollution, its more dangerous and less healthier than countrylife, in the city you waste less time and become more successful, and if you have a lot of stress you can just take a vacation in a relaxing place. I think that the city is the best option because of this.