How then they go to work? I understand that in the USA public transportation is quite lacking except for a few big cities.
So, choose to live on an artery near a bus stop, and that entire artery becomes available to you for employment without owning a car.
It’s true, you can’t get to arbitrary residential addresses without long walks, but commerce is on the arteries. Try to avoid needing transfers to a different artery. That is a huge time sink.
Newer suburbs, 20+ miles from city center, are different. They only have commerce at the intersection of arteries or specialized areas and this does not work for bus riding.
This is all for fungible employees in fungible jobs. If you are a skilled professional in a suburban employment your pay will be high enough to have a car and live in the quieter areas off the arteries.
I won't pretend it's the greatest but I've lived in quite a few 2nd and 3rd tier US cities like Phoenix, Atlanta, Jacksonville Fl, Nashville, Knoxville TN and quite a few others and the buses are certainly capable of getting you to work and back. Everywhere I've lived the buses run 7 days a week from early in the AM to late at night and some run 24 hours a day in Atlanta. Pretty much any bus route will see a bus come along every 20 or 30 minutes with some stretching out to 45 minutes. Some routes though will see a bus every 5 or 10 minutes depending on the day and time.
Even in Jacksonville FL which has more land area I think any other US city, there is no urban part of the city that is more than a half mile from a bus stop. You can even take a bus from the north extreme end of the city to the extreme south, where a shuttle connects that will then take you to St. Augustine (a suburb of Jacksonville), a grand total of probably 60 miles, for less than $4 total. That doesn't seem too bad. Is it perfect? No. But I think the public transportation system problems may be a little overblown at least in the cities I've lived in.
On the other hand I pay a bit more in rent to live somewhere with easy bike and public transport options.
This is of course an average. Where you live and what sort of car you choose matters a lot. Putting aside luxury, and new cars and focusing on just transportation… there is a tradeoff between average daily cost of ownership and reliability. If you can say "sorry, won't be to work on time, my car died" without jeopardizing your income then you can live the exciting life of the $500 car. My daughter's friends who do this get by on something like $4-5/day to pay for the car (excluding "mandatory" insurance, which is around $3/day, they pay that sometimes, or not depending on their work situation). Fix the small things, maybe with help from friends, sell it to the scrap yard and get another when the big repair comes.