Not just in China. China is maybe the most interesting point of comparison with big cities in the US, though, since its cities are both much denser than most AND more sprawling than most.
And I don't follow your second question. If the trains OR freeways are full of people who can't afford to live closer to their jobs and have hours-long commutes, isn't that bad? And if it can happen even with extensive public transit, what does that tell us about fundamental assumptions about "city should grow forever, number must always go up!"?
The urban mega cities are a prop that the CCP puts on display for the world. There's a reason that China's GDP-per-capita lands somewhere between Kazakhstan and Cuba.I would know because I've been there. If you go to a random exurban part of China you're going to find people living in makeshift tin structures, a lack of running water, oxcarts used as serious transportation, and a society that is functionally in the 1930s.
The CCP are masters of propaganda though, and flood Youtube and social media with influencers riding around on maglev trains and showing off new airports and architecture. Even on American Social Media, if you look for videos of "The Real China", or "Chinese Poverty" you'll get carefully curated propaganda that does not line up with what I saw first hand.
The SerpentZA YouTube channel is somewhat sensationalist, but it has good firsthand videos showing the real China from someone who lived there for years and is fluent in Mandarin. The reality is a lot darker than what most Westerners see.
And I don't follow your second question. If the trains OR freeways are full of people who can't afford to live closer to their jobs and have hours-long commutes, isn't that bad? And if it can happen even with extensive public transit, what does that tell us about fundamental assumptions about "city should grow forever, number must always go up!"?