Expanded explanation. Due to economics you'd invest in a more expensive technology, using more manual labor, having less free time to think to more advance tech, which in turn leads to slower development. Using more manual labor would also, in turn, lead to less need for coal and oil demand and that would mean lesser climate change problem. My 2 cents
How can collective transportation be more expensive than cars, as a whole? Most western countries had really well connected railroads going in all the very small towns and did that for pennies compared to the overall price of car society.
The overall cost of cars is not just the individual car. It's also infrastructure that caters to cars, which requires roads everywhere (otherwise your car is pretty useless), parking spaces.. etc..
While i agree with the conclusion (better for the environment, and probably for everything else), and i agree manual labor is usually (though not always) preferable to industrialized labor, i don't understand why collective transportation would require more manual labor.
So it sounds like they don't dream of it in the same way that many people in the US don't dream of being chauffeured everywhere in an Uber. It's so expensive that it's not even within the realm of possibility.
Having "good" public transit as an option is very nice. I once lived in a city like that. But it's not hard to see why a lot of people (and not just in the US) choose suburbs and sitting in traffic as the option that sucks less than the others.