That's one factor. I would say though, that I do not generally see people dropping things in the street every day in front of people property - for them to swipe. On the other end, I have found a direct link between the garbage collection nights and the number of items flying in the street the day after. I see this over and over and over again. The items stay on the sidewalks, end up at the curb and are accumulating over times. I suspect it would not take long to build the evidence.
These items end up blocking our sewers. I think the City (and possibly Suez through threat of legal action) should make sure garbage collection is done appropriately, if necessary through adjustment in schedule or a revised contract - so it is addressed fairly on both sides. That's my personal opinion.

Waaaayyyy back in the day, when more people owned the residences that they lived in it was pretty commonplace to see people sweeping the sidewalk and street in front of their homes. Anyone see any of that lately?

I don't know the answers, but echo both your concerns and questions.

I feel like garbage on the streets has gotten worst. No matter how many ties I clean around my building there is always more garbage blowing around.
Can anyone tell me if:
Buildings are required to keep their sidewalks and tree planters clean? Who can I contact if they are not ?
What about businesses and parking lots? The one on Columbus and Barrow is lined with garbage that blows all over.
What can I do about buildings putting out garbage on the wrong night?
Who is responsible for planting trees in empty sidewalk squares?

thank you