Stop exaggerating. I've lived in NYC my whole life and it was not as bad as you're making it seem. Not even close. Maybe in very isolated areas in NYC. But the norm? Not even close.
In the 1970s, the city was on the verge of bankruptcy and a huge amount of city services suffered from disinvestment, which also plagued the subways well into the 1980s. A recession began in 1969 that did not begin to lift until 1977, which negatively impacted many of the city’s industries (trucking had all but destroyed South Street Seaport, the fish markets and the freight railroads). A lot of people felt unsafe, and many folks left, sometimes leaving entire blocks of buildings abandoned.
Midway through the decade, New York State took over most of the city’s finances, and immediately those in charge fired 60,000 municipal employees, cut a quarter of teachers, put an end to free tuition at CUNY and marked a significant policy change whereby the private interests of the city trumped the public ones. This coincided with the aforementioned policy of disinvestment, prompting numerous strikes by the Sanitation Department, who at certain points refused to pick up trash at all, letting it rot on the streets for days, prompting the nickname “stink city.” By the middle of the decade, most of the fires in the city were arson, and there were yearly riots; some building owners paid teenagers to set their buildings on fire so they could collect the insurance money. The most famous riot,
the 1977 Blackout, saw looting in 31 neighborhoods and caused over $300 million in damages in less than 25 hours, with more than 3,700 people arrested. https://www.reddit.com/r/AskHistorians/comments/1q81vv/was_new_york_of_the_1970s_the_shithole_movies/
