You do realize that Europe has 3X the population density (and subsequent urbanization) as the US right? That alone explains literally every difference between Europe and America, in everything from public transportation down to socialist political leaning.

Yes, as an engineer, it is absolutely more “efficient” if everyone lived in small government subsidized boxes, in centrally planned cities, taking centrally planned transport to only the places you’ve decided they should go.

However, central planning and praying at the god of efficiency has its downsides. Namely a total lack of innovation or people having children. It turns out having 2 crying babies in your tiny 2 bedroom apartment and taking 2 trains and a bus to the pediatrician kind of sucks.