Why do many people choose to live in cities?

I'd say most people move to cities for better job opportunities. That's because cities like Shanghai have more companies and industries, so there's simply more options for career growth. For example, as a UI designer, I wouldn't have found my current position if I'd stayed in my hometown - the tech scene here is much more developed. That said, the competition is fierce too - you really have to stand out to get those good positions. The trade-off is higher living costs, but for many young professionals, it's worth it for the career prospects.