I'd be interested to hear from people in large European cities and whether public drug use and homelessness are as big of an issue there as they are here. I've only been to a handful of European cities, and none seem to struggle with either to the extent we see in larger cities in the US.
Seriously though, leftist cities like Berlin have the same problems as the US, although on a much smaller scale. It's what D. Trump would call an shithole. Bavaria is clean, because we enforce a restrictive drug policy.
As for homeless, we've got some, but they're voluntarily so. The shelters don't accept alcohol, drugs nor dogs. They gather far away from any business/residintial area. (In my local town, under a bridge between a river and an animal shelter.)