it is far easier to promise service than it is to pay for it. in that regard making promises to the users of the service and workers is one thing, when it comes to paying the bill they always kick the can down the road.

NYC is the only American city which relies on heavy transit, just a little more than half the people working there use it. Only one other city crests ten percent and the after that its five percent and down.

It is the most expensive transportation option available to commuters at all stages when you calculate it per passenger mile, this is with subsidies included. Even building all those roads the automobile less that a fourth of the cost and most public transit will be superseded by autonomous cars and buses; the later which can adapt to changing needs that subway and heavy rail cannot.

Besides all the deferred maintenance and NYC is not alone in this, many lines are tens of billions in deferred maintenance, many lines face hundreds of millions with a few at a billion in underfunded pensions. Worse, subsidies have not increased ridership but instead employment. When most lines came about in the hay days of such it was nearly 60k riders per worker, that has fallen to less than 30k riders being served per worker.

the simple fact is that such transit is expensive to build and maintain and even with incredible subsidy they cannot get enough people to ride it though NYC gets close. NYC has the same problem the rest do, no one wants to pay anywhere near what the actual cost is per passenger mile to use it.