USA has: higher debt per capita, higher unemployment and higher population percentage under the poverty line than the UK. Maybe it has a higher GDP per capita but also take into account how expensive everything is there.
For the more unfortunate people in the US they can't get help with housing or benefits any near as much as you can in the UK. Also I'm from England take that into account, Wales, Scotland and Northern Ireland significantly bring the per capita down. The UK is not a country remember that.