

The problem is that federal income taxes are generally paid directly by employers to the federal government. It’s not clear by what mechanism states and/or cities might withhold them.
It’s true that the State of New York, and NYC are both large employers, so hypothetically I guess they could refuse to collect income taxes from their employees on behalf of the federal government, but certainly the IRS would still hold the individual taxpayers responsible for those taxes at the end of the year.
It’s gonna be real shitty when this bubble bursts.