You may not realize this, but there are numerous rail systems around the world that are not subsidized and are in fact profitable. See Japan, for instance
Almost all rail in Japan is subsidized, directly and indirectly. Yes the single line that is the Tokaido Shinkansen is immensely profitable; even then, JR Central does not pay market-rate interest on even the portion of the construction debt that was not absorbed by the government.
This is not true: Japan's rail systems are profitable on a cash-accounting basis (e.g. fares add up to more than day-to-day operating costs), but not if you include the immense cost of building the rail itself. When Japan privatized its rail, part of the privatization agreement included the government assuming most of the debts from construction, so the private entities wouldn't have them on their books. If you were to include these costs, Japan's private rails wouldn't even be close to profitable.
The MTA does not overpay when you compare to other employers in central NYC. It's an extremely expensive city due to housing policy failures.
As for commercialising the stations, does the MTA try to do so and fail, or are they forbidden from doing so effectively (often by the same people who are pushing the narrative that there is something wrong with the organisation)?
The point is that the MTA is deeply in the red even though it still charges significant fares. Meanwhile, systems like the London Tube manage to recover at least their operating costs without charging fares that are much if at all higher.
According to a quick search the nyc subway is $2.90 rising to $3 next year. This is comparable to, but slightly less than a zone 1 off peak ticket in London at £2.70. Most journeys are more expensive (on the train, busses are pretty cheap here)