When I lived in Philly, I loved the train service. It was perfect to go from Philly to DC, Philly to New York City. But it only works in scenarios like that. Anywhere outside the Acela corridor, it’s useless — too many stops, too many changes. While a trip to New York would be a little over an hour, the rest of the trip if you wanted to head to Boston would be an all-day affair.
Unless Amtrak can provide non-stop point-to-point service, they will never truly compete against the airlines.
The real idea is for private railroads to do that.
There is a lot less rail service between New York and Philadelphia than there used to be. There used to be the Reading’s “Crusader” for example, which was a limited-stop train running at top speeds of 90 mph (sometimes faster) and did not run on what is now the “Acela corridor” as you term it (former Pennsylvania Railroad). Sadly, under government control, the “Crusader” ended as a two-car noisy and rather smelly RDC train from Newark Penn Station to Reading Terminal operated by Conrail.
The only time I have ever considered taking the Acella train was to go to midtown Manhattan. However, by the time I drove to south station in Boston and parked, waited for the train, I could have driven to Hartford(half way) and then another 2 hrs to Manhattan.
The other consideration is what it costs to PARK your car in Manhattan. Last time it was around $50/day. Don’t even think about bringing a big vehicle like a Suburban because that will cost at least $100/day to park in Manhattan. Plus the valet will steal anything in your car like loose change.
Trains only work if you live in the city and your destination is another city.