Housing here skews old: 73.0% predates 1980 against a national 49.7%. Those 7,409,947 households renovate rather than rebuild, and renovation is the single most reliable generator of hauling work.
48.5% of New York City households rent rather than own, against 34.8% nationally. Across the metro's 7,409,947 households that is the largest single source of turnover work: apartment cleanouts, setouts and lockouts, and bulk pickups that recur with every lease cycle rather than arriving once.
New York City has 7,409,947 households across a population of 19,798,537. Junk removal demand tracks households more closely than anything else: people move, renovate, downsize and clear out, and every one of those is a job for someone with a truck and a crew.
Where these figures come from
Every number in these paragraphs is a Census figure for the New York City metro, compared with the national figure from the same table.