In my opinion, living in the city both have its own advantages and disadvantages but today i will only discuss about the disadvantages
First and foremost, although in the big city has a lot of job opportunities, there are also has people who be competing with you for your job.Today you might have a job but tomorrow you might be employed. By this i mean : you might be qualified for a job, but if your boss see another people who are want your position are more qualified than you. You might lose your job. Maybe they have more job experience than you or they have a higher degree than you.
Secondly, it is undeniable that the overcrowded are the realization for all big city. This leads into 2 problems : traffic jams and the cost of living. If there are a lot of people on the road in the same time and it make you can't move, it's called traffic jams. Especially in tthe rust hour, it is very difficult to get from a given place to another. Next is the cost of living,the cost of living in the big city are very high. It may "cost you an arm and a leg" to pay for your living. People have to spend more money on foods, drinks, clothes and other activities like entertainment, traveling while the salary hasn't been much improved
Finally is the pollution. Pollution is a sad reality for big city life. Unfortunately, pollution may always be a problem in the big city despite many solutions have been proposed. For example, noise pollution can cause the bad effect to the activity and people's health. High noise levels can affect to human cardiovascular, rises in blood pressure and many things else.
In short,although living in the city has a lot of advantages,it also has it disadvantages so people have to struggle a lot if they want to live in the city