What would the police do about it, arrest the homeless person? Would the local criminal justice system have the capacity to charge and convict them if the cops did so? Many of the cities where visible homelessness is a problem also have shortages of cops that cause them to triage what sorts of incidents they send an officer to respond to?
I probably would not have called the police after this person if this happened to me, because I expect they would do nothing about it.
Not anywhere being discussed here. Chicago it may or may not get added to a dispatch call. Chances of it ever being followed up on are slim. At best you might get a patrol car rolling through a couple hours later to mark the ticket solved.
It’s a pretty common experience for anyone who is out and about using public transit in public spaces. They know nothing will be done to the suspect so what’s the point of bothering to respond at all?
I probably would not have called the police after this person if this happened to me, because I expect they would do nothing about it.