In my town they have a snow blower on a small tractor trying to clear walking routes to school. But there always places it cant handle such as a narrow spot or tree or post obstructions on the sidewalk. Maybe a car not pulled in far enough. Kids have to walk in the street until the constriction is passed, unless someone shovels
I’m sure the same is true in nyc: various machinery in most places, but some just can’t fit a machine for various reasons.
Note that they didn’t hire millions of shovelers. If they didn’t have machines doing most of the work, they’d still be shovelling
How much public works? It’s predictable that there’s snow, so you have equipment. Sometimes there’s more do you prepare for more. But it’s expensive equipment that needs to be purchased, maintained, stored and operated. Most of that expense is year round but you see benefits only a few times per year. Do you invest enough money year round to cover a once a year storm? A once every ten years storm? What about a 100 year storm? We have had those recently but that’s a lot of equipment
Meanwhile these shovelers aren’t on payroll most of the year, have no special equipment, don’t need maintenance, etc. I d expect they’d quickly become cheaper