Driving is also heavily subsidized by the fact that much of the cost of driving is externalized. When someone drives the fumes coming out of their car damage the health of everyone around them, that cost is paid for by everyone and not just the person driving so there is very little incentive to stop doing it.

If you want to talk externalities then stress, frustration and mental health need to be taken into account on the public transit side of the equation.

I'd put up with a hell of a lot of air pollution if it made the trains timely and not crowded and I'm not the only one who'd make that tradeoff.

Stress, frustration and mental health are costs I have only ever experienced in a car.

Riding my bike to work was one of the best things I ever did for my mental and physical health.

Pre-tax transport benefit plans at the federal level have had equivalent transit/parking amounts since 2016; not that the city has much control over that.

NYC's own pre-tax program explicitly doesn't include parking. It's also probably worth mentioning that the city has a tax on off-street parking at 18.375% in Manhattan.