They have to live somewhere. As MAS said, they are going to places in which they get the best treatment. Let's start with us all agreeing on that.
The issue is whether it is our future. Specifically, your post asked if this was our future (presumably meaning would we all have this if all places became as progressive as San Francisco). My answer is no. If you have 100 homeless, and they all go to San Francisco because it is very progressive, then what happens if you make 100 cities just as progressive?
Those 100 homeless are now spread out over the 100 cities (one per city). That means the scenes you see of San Francisco would not be our "progressive future" because no city would have the concentration of them that SF has now.