> I assume that people in the US on average aren't worse than people in other countries tries so to me it seems that there is a problem with policies in the US causing higher crime rates.

Why do you assume that? Murder rates in the US were 10 times higher than in continental Europe even at the beginning of the 20th century, long before support programs existed on either side of the pond. (Indeed, in Europe, all the modern support systems, government welfare, and gun control hasn’t reduced crime—at least homicide rates—at all. Homicide rates in England, France, and Sweden hit modern levels in the 1920s: https://ourworldindata.org/uploads/2013/03/homicide-rates-in.... Germany and Italy saw major drops in the early 20th century, but I’d probably chalk that up to increased political stability.)