If you have bullet trains and hyperloops connecting to Penn Station, can New York City be much much larger? The affordable housing issue kind of goes away with that.
Urbanization is one of the solutions to climate change. More people living in big cities is a good idea from the environmental viewpoint.
The Ultimate Megacity: 100 Million People
San Francisco's Fog Over Growth
the advantages of agglomeration. Put lots of highly skilled, highly productive, highly innovative people together in the same place and the economic gains are huge. ...... on the whole it’s fair to say that San Francisco hasn’t exactly embraced the role of boomtown. There are voter-imposed limits on office construction, new housing developments usually face protests and litigation, and local politics boasts a strong contingent of “progressives” whose main goal seems to be keeping the city from changing. ..... homeowners favor zoning ordinances and other growth restrictions because they keep house prices up. ...... 65 percent of the city’s housing units are rentals, and 75 percent of those are subject to rent control. Most of the San Franciscans who oppose new development do so apparently not to maximize the value of their property but to minimize the odds that they will be forced out of their apartments or otherwise priced out of the city. ....... growth restrictions restrict growth not just locally but on a national level .......
lowering the regulatory constraints on new housing in just San Francisco, San Jose and New York to the level of the median city would lift U.S. gross domestic product by 9.5 percent....... land-use regulations were also driving up inequality and reducing economic mobility