I livde in NYC through during the long slide into crime and filth and witnessed a turn around. I’ve traveled there frequently as NYC recovered. While graffiti is pretty much gone there, you can still find it. You see it in Queens, Brooklyn, the Bronx and Staten Island, as well as Jersey City.
I see a lot of graffiti in Los Angeles now and in Washington, D.C. New York is cleaner than it used to be, but is still a pretty dirty city where many people use the street as a trash can an litter is constantly blowing with wind along the streets an din the parks. You realize this if you visit Chicago, which is very clean and neat.
No, I’m sorry, but there is not much graffiti in New York and it’s not a particularly dirty city. I don’t know where you’ve seen graffiti in Jersey City (or Weehawken, for that matter); I travel every other day to NYC by car and never see ANY graffiti.
By the way, I have a little trouble believing you are up in the Bronx that much. Or Staten Island. Or Queens. Maybe Brooklyn - that’s a hot spot for residents and tourists.