But that's the ultimate problem to solve. Build dense cities, and people will (a) want to live there and (b) will want to use transit and (c) transit will make

But that's the ultimate problem to solve. Build dense cities, and people will (a) want to live there and (b) will want to use transit and (c) transit will make the most sense. The city density issue is one completely controlled by the government. Developers are incentivized to produce high-density housing, because it yields more money. Cities don't want it.