Extending lines clearly isn't in the scope of the commenter; the 7 already got an extension to Hudson Yards a few years back and the first phase of the 2nd Ave extension came into operation recently as well.

Speaking from my own selfish perspective, I think fixing the lines we do have is more of a priority than building new ones.

Only part of the 7 extension was completed. They didn’t complete one of the stations because of cost.

You’re doing that thing where you think we can only do one or the other.

It takes a long time to fix existing subways. You can’t simply close them down. Look at the L train.

There’s no reason we can’t also expand the subway. Depending on where you build, it could go a lot faster.

That could be a great idea, luckily the path train exists, although I've never commuted on it so I can't speak to its reliability.