I don't understand why people still live in big cities

Most big cities around the world are a playground for drug addicts and criminals. They are dirty, noisy and there are way too many people.

As soon as you live your flat and actually want to do something, it will cost you a fortune.

Job opportunities? Meh. Ever heard about home office?

So why would you still live in a crowded city if you can live in a small town/country side?