Megacities: overpopulation, traffic and crowds

A megacity is defined as a very large city, typically one with a population of over 10 million people. Throughout my life and career, I have lived in big cities, so I consider myself mainly a city girl. Although born in a small rustic town in Laguna, my family moved to Metro Manila when I was only 3 years old and lived there until my early 40s.
I then had the opportunity to do my Ph D at the University of Chicago, so I also experienced life in the Midwest. Then my professional career with the United Nations took me to New York City, and to most of the top 20 megacities in the world, like Delhi, Bangkok,  Dhaka, Moscow, Mexico, Beijing, Karachi, Seoul, Jakarta, and Tokyo.
The UN reports that more than half of the world's citizens live in urban areas, a figure expected to reach nearly 70 percent by 2050. Globally, 1 in 8 of those city dwellers lives in a megacity. And what is common about all these places - overpopulation, congestion, traffic.. and often described as hectic, crowded and chaotic.
A friend of mine who lives in Europe visited NYC for the first time and was shocked. She said, this is New York city? It's all buildings and people! and the Manhattan traffic is awful!
At the same time, these big cities offer many things - jobs, shops, cultural places, great universities, structural icons and touristic places. Hence, they have a very strong pull or influence on people to live, work, study, or migrate to those places.
One author wrote about megacities and said, "I am fascinated that so many people can co-exist in such crowded places! There's never enough space. But there's also a current of inventiveness, a sense of community" (in a strange way..). In NYC, people who don't know each other often have a sense of being one, as "Nuyokers".
In NYC which houses the United Nations, an advertisement for a credit card once said.."New York is the only place in the world where there are as many restaurants to please the palate as there are member nations of the UN". This is true, wherever you come from, when you come to New York, you will always find a restaurant to eat something familiar to your taste, if not actually, an authentic restaurant from your native country.
Don't get me wrong, I also love the rural areas.. and in fact, I always enjoy visiting my hometown of about 5 million people whenever I go home to the Philippines, but there's is something about being in Metro Manila that gives me security.. there's always shops, restaurants, and places to visit, and to do things with family and friends.
Having lived also in Ulaanbatoor which is a city with only about a million people, I can say there's so much beauty in it that I would love to go back to many times over. The people are so nice and the culture, unique. Going out of the city though opens up a whole new world of beautiful nature, blue skies, mountains. I can never forget those hospitable families in colorful gers on the gobi deserts, who welcomed us during field visits with local tea and milk candies. It isn't a megacity, but UB is also not spared of traffic and overcrowding especially in the more popular residential and commercial areas.
Overall, megacities provide useful indicators  of the economic and social activities in any country. It could be seen as progress in many ways, but critics, also have referred to some aspects (referring to poverty, squatters, unemployment, etc) as critical measures of underdevelopment.