I don't mean to be rude, but you need to get out of your bubble and see how the rest of the world lives. I hope you're living your dream, but everyone has different dreams, constraints, etc and they're not all inferior because they are different from yours.
What are some cities with decent enough public transportation and urban planning for pedestrians that also don’t suffer from lack of housing/exhorbitant housing prices? The top cities I can think of that satisfy the former unfortunately also have the latter.
Some of us have both! It'd be nice if it were as simple a tradeoff as that.
Chicago
There are also a number of small cities that have decent enough public transportation and are fairly cheap, but fall short on job availability.
In the US, Chicago, Philadelphia and possibly Baltimore.
In other countries, many many more cities.
There isn't enough room for everybody to do that and, without big changes in zoning laws, there never will be.
That's a non-starter for a lot of folks. Intellectual pursuit, family obligations, money, or a combination of those things can conspire to keep people somewhere whether they like their situation or not. I left academia so I could move where I please, but there was a steep price attached to that, and I wouldn't expect everyone to make the same decision.
I don't believe 200 million people in NYC would lessen the impact of the sprawl effect.