So fix MTA. Their system expansion budget is currently $15B/year, so at the costs of a low-wage, low-regulation, totally ununionized country like (checks notes) Norway, they could be building 60 km of new lines per year.
Just like that we'll fix the MTA with the wave of a hand. The MTA that spent billions and a decade for a couple of stations. In a mono party City/State where unions are tied to the party machine. Good luck.
It's not like infrastructure is free outside of Manhattan.
Federal, state and local spending in the US on roads adds up to around a quarter of a trillion dollars per year.