This BBC article about traffic congestion in Sao Paulo carries on like 180km traffic jams are an inescapable fact of life there and congestion is an insoluble problem. They even find a professor of engineering and transport from a Sao Paulo uni to say that "No city in the world will ever manage to end congestion".
Completely ending traffic congestion may be very difficult, but there are certainly cities who have reduced it substantially by doing things which Sao Paulo has chosen not to do. Congestion charging in Stockholm, Singapore and London has sharply reduced the level of traffic in their inner cities, and there is no doubt that if they were to whack up the prices that traffic would fall even further. Many cities have also built comprehensive, high quality rail systems, and given buses priority express lanes on main roads. But in Sao Paulo, instead of a congestion charge they introduced a rotating car number-plate ban which reduced traffic in the short term but mainly encouraged people to buy more cars. The metro system is far too small given the size of the city. And historically their buses haven't been given enough priority over other traffic and so suffer from the same congestion as cars. Hence, huge traffic jams.
I'm not suggesting these are easy choices, especially for a rapidly expanding city like Sao Paulo. Most cities are not fortunate enough to have built a huge underground system over a hundred years ago when it was nice and cheap, like London did. Sao Paulo now has a growing bus rapid transit system and big plans to expand the metro, but because Brazil is a democratic country where most people have the right not to be turfed off their land, building vast infrastructure projects is much harder and slower than it is in, say, China. Likewise, it's not easy to find the money to build a subway network big enough to adequately serve a city of 20 million people, or to convince drivers that they should pay to use roads they previously used for free. Those kinds of things are very hard, which is probably why more cities don't choose to do them.
But one reason they're hard is that many people are not convinced they are worthwhile, and that in turn is partly because the public discourse around these issues seems wilfully uninformed. There are solutions available which are workable and demonstrably effective. It's one thing to consider and reject them, but to pretend they don't exist is something else altogether.