It's not hard to find places where a 40min commute in a car turns into 2-3 hours using public transport.
Public transport is also not as reliable in places with extreme weather especially cold.
Have fun waiting for a bus in an open bus stop at -10c...
Certainly in rural areas and in wider peripheral suburban areas public transport is less useful. But in actual cities (London, Paris, Istanbul, etc.) with a high density of people and their residences, public transport is the way to go. I don't know much about American cities, but if we got a comprehensive and functional system of metros, buses and boats here in Istanbul, where some of you would classify as a part of the third world, I guess you are capable of doing it in the US too.
London is probably a "bad" example, I live in London and sure the public transport is probably in the top 5 in the world, so is Tokyo and Paris. But what many cities with good public transport have in common is that they had public transportation for a long time, were designed / rebuilt with that in mind when it was manageable and are relatively small for their population density.
I would not want to be the one that has to design a public transport system for a sprawling city like LA where the greater LA area covers nearly 90,000 square kilometers for a size comparison the entirety of England is 130,000 sq/km.....
https://www.bloomberg.com/news/articles/2016-08-15/uber-and-...