This is an issue in some cities in western Europe also, there are no free restrooms available. No wonder everything around train/subway stations smells like piss.

What do they do in Germany? Their public toilets are amazing, but not free.

I suspect the answer is that they don't have that many people who have these sorts of issues in the first place, but at the same time more social spending doesn't seem to be the issue, as California spend a fortune on the homeless issue and gets relatively little for it, and the most common length of time to be homeless is one day.