But there is no amount of money the MTA can’t waste. The MTA is a bloated, incompetent, and completely unsalvageable organization. The subway system in NYC will never be fixed, properly upgraded, or properly maintained while the MTA is in charge.
At minimum the actual construction and maintenance wings should be privatized.
The Bay Area Caltrain was actually private until fairly recently (1985), when the operator gave up and the state took it over.
However, even the state doesn't want to operate it, and there was a review around 2010. But Stanford University weighed in (over 10,000 riders/day) and the review stopped.
You would have to look at the numbers for NY.
Note that the "MTA" was originally two private entities that ran out of money building the system.
And the bulk of the NYC subways were built and operated by competing private companies for decades. That stopped when first the city regulated them to the point that they could not make improvements, and then the city nationalized them.