Americans own cars because most of them live in single-family houses on large plots of land, and that doesn't make public transit for daily commuting a realistic possibility. In Paris car ownership is very low, maybe 1/3 of adults, but in rural France the car ownership rate is easily 95%+. I haven't seen a single developed area in the world that has violated the rule that low density = high car ownership and vice versa.
The other rule that I have never seen violated is that the large majority of middle and upper income people do not want to live near low income people, due to crime or other reasons. In Europe, poor people live in the suburbs, so the middle income live in the city with high density housing. In the US and some other places (south asia), low income people live near the business center, so the middle income live in low density housing in the suburbs. These are for historical reasons and cannot be easily changed.
The real reason Americans own cars is because we’re rich enough to afford a more expensive and more convenient system. Public Transit at scale is surprisingly cheap when compared to all the costs associated with car ownership * 10’s of thousands of people in even a fairly small community.
That quite a straw man, my friend!
A bus that runs twice per day, with a fixed number of passengers, all of which go to the same destination... that's not really the kind of service that can get you free of private cars!
Also these busses generally go by homes 4x times per day twice for middle school and twice for high school. They don’t go by every home every time if no kid lives on a street, but in suburbs there’s a lot of school bus traffic.
Expanding that to adults would require more trips and a backbone network between collection points. But, the point still stands that sending busses to most homes in America say 40x or more times a day is hardly impossible when we are already sending them 8x a day on the cheap. Being inconvenient compared to a more expensive car option is the core reason why this doesn’t happen.