> Station overcrowding can be fixed

Yeah, usually by totally rebuilding the station. Easier said than done when you already have a skyscraper built over top of you. NYC is trying to revamp a lot of its current stations that see magnitudes of traffic more than they were designed to on a daily basis, and that's a massive undertaking.

What about digging more parallel tunnels and keeping with smaller stations?

That's good for track maintenance too.

Have you seen the location this is in? That should help answer, you would be trying to dig under skyscrapers.

What way of fixing station overcrowding are you thinking of?

Running more trains, mostly.

The 7 is already projected to run at peak frequencies in the existing plan; signal upgrades help a bit but not a lot at a terminal station. The rest of the 7 isn't capable of running trains much more often.

the 7 train only runs at 24 trains per hour. Other systems, even ones in the US, run upwards of 30 trains per hour. For example, the Red Line in Chicago runs every two minutes during rush hour and that is capped due to the Belmont junction. It has the same terminal station layout at 95th street as Hudson Yards.

For 2.5 billion dollars, I bet they could have extended the system, not built some insane labyrinth 150 feet underground and improved signaling to run 30 trains per hour and maybe even built that 2nd station they had to cut due to cost.

They could not have both built a station and extended the system for their budget, no.

The new signaling for the 7 will already get them to 30 trains an hour, and that will not be enough in 30 years, much less 100.

The NYC Subway had a yearly ridership of over 2 billion in 1946, higher than it is today (pre-covid). One could say that we should be building a subway that can transport 5 billion riders per year and have six tracks on every line but that would be silly and there's no legitimate reason why that would be the case.

I'm not sure what you're getting at here. NYC is growing steadily, especially around that station.