All studies show that free public transit is a bad idea. There is a reason no country provides it. People mis-treat free things. When you ask them to pay for it, it enforces civic contracts. With contactless terminals in place, a free MTA benefits no one. It's also difficult to get additional funding to improve something that's free.

An MTA monthly pass is 130$. That's the price of a single uber round-trip to JFK. NYC also allows employers to provide commuter benefits tax-free.

It's cheap enough.