I lived in Helsinki for a while. It's not a great place to be homeless because despite recently mild winters, it's just not a nice place to be living outside when most of the year it can drop to freezing temperatures (or well below) at night. Having people on the street freezing to death in the middle of the winter is not something that is very practical. And of course the whole system ensures that people are mostly taken care off regardless of their issues (alcohol, drugs, psychological issues, etc.). Food, shelter, medical care etc. are easily accessible.