I'm not an expert but there are large swathes of rough sleepers in SF, SJ, NY, Austin, LA, etc. And even though the % of population in the US who are classified as homeless in the US is less than e.g. UK, there's nothing on that scale of rough sleepers scale in comparable or larger cities like London, Paris (maybe 17de?), etc.

I don't know if the definitions of homelessness plays a part in the different %s but the suffering of homelessness seems higher in the US than EU.