All cities attract homeless people to a greater or lesser extent. It's easier to blend in and live off the system's detritus in a large city than in a rural area or small town, if you don't have any friends or family willing to support you.
What end game are you trying to get at?
Rich European countries which have solved this problem don't do it by putting all the homeless in Paris or Berlin. They're distributed throughout urban, suburban, and rural areas of the country, which is what we need to do.
It's cities that have the jobs and make policies that drive up the cost of housing. There's much that can be done at the city level.