Yeah, I'm sure you're right - it's a global problem.
I've not been to the US (just working in Vegas and LA) for 25 years. The problem seems to have gotten much worse since then; I've seen the LA, SF, etc, tent cities. In the US, maybe a lot of the homeless folk have drug related problems rather than non-drug related mental health issues? Just a guess.
The government/schooling system/other (such as billionaires and corporations) could be doing a lot more, but we're increasingly a greed focused selfish culture - this also seems global.