> "Your grandkids might some day dream of having accessible subway stations" is such a civilizational failure that we've just silently accepted
I agree that the timelines are a real problem, but that's for the long tail. The major transfer stations are mostly there today and the remaining few are on track to get there in the next few years.
NYC has a lot of stations. There are some that basically cannot be made fully compliant with the full spectrum of ADA accessibility requirements, which are actually on the more comprehensive side of the spectrum compared to other countries.
Some of it makes more sense when you see it. There's a station built underneath the pillars of a bridge. Right now they're trying to figure out how to add a second entrance and exit as a first step, but as you can imagine operating on a station under a bridge is hard. It's also the only station in the neighborhood, so you can't just shut it down for a year. Getting it to the point of having full elevator/escalator and other ADA compliant requirements for new construction is basically out of the question without having the most out of control construction project you've seen.
So the long tail of stations are going to take a very long time to get updated, if ever.