Don't get me wrong, mixed-use zoning is great, but people rarely live next to their jobs. It's difficult to get both people in a two income household to work close to each other; where people want to live vs. where their employer wants to locate is rarely the same, etc. Tokyo, for example, is very mixed-use and very polycentric, but has some famously bad commutes.

Unfortunately NY is set up as a centralized archipelago; existing transport infrastructure is pretty much saturated, and encouraging outlying areas to gain jobs is not workable because Manhattan is the only place accessible to every single part of the metro area within one or two seats on public transport.

It's hard to use the tax boost to add more mass transit, because you'd have to bond based on projected revenues, which is fickle at best. The only places that tie redevelopment and transit together successfully seem to be in Hong Kong and Japan, but in those places the mass transit operator either already owned the land being redeveloped, or got it for pennies on the dollar as a de facto public subsidy, which would be impossible in the US due to the Just Compensation clause of the Fifth Amendment.