The problem seems fixable, but as others have said, people will have to take some lumps.
A certain political figure with strong (both bad and good) ties to NYC has harped for a couple of years about a federal infrastructure bill. I think the phrase "third world" was used to describe the problem.
No reason why America's Greatest City (tm) could not wring a couple of bil out of the feds to start upgrading their subways. Move back to the first world, you might say.
In turn, because we're talking about a transaction, the MTA might also need to move out of a "third world" mentality. We can safely assume some of their payroll is spent on political favors. Maybe this "death spiral" talk will motivate the agency to make a least a token gesture towards good use of their riders dollars.
Maybe.