I hated commuting to NYC on trains from New Jersey. The service was terrible and the peak hour trains were usually packed beyond standing-room-only.
FWIW ... I'm a civil engineer by trade, and I did some work on the preliminary design of the LIRR Grand Central extension project way back in the 1990s. I think it was officially called the LIRR East Side Access Project.
I've been waiting for this for years as I have a branch office on Long Island which previously required me to get to Penn Station to catch a LIRR train out there. My main office is on Lexington Ave just across from Grand Central. So now it is very easy to get to Long Island from my primary office.
The New Jersey commuters have the worse of it. Many of them drive in, which to me is horrifying as I would never want to take my personal car into Manhattan.
The Metro North is the best of the three and my main commute (up to Westport, CT). The LIRR is also pretty reliable though they have some real growing pains due to this East Side Access opening up. They've had to split the trains between Penn and Grand Station resulting in many passengers having to get off at Jamaica to catch a train to their final destination. Sometimes they only have a minute or two to run up the stairs and across the ramp to get to the track their next train is on.
They will get it right eventually.
I could never be in such close proximity to strangers. Not for a million dollars. And certainly not for more than a minute or so. The busses, trains, and planes I used to take (out west) were uncrowded to the point that a passenger was seated every three rows or so, if even that. And that seemed close to maximum tolerable density. Very, very, rarely did I ever have to share a row of seats.