Acela takes 3h44m from Boston to New York. Not much faster than the scheduled buses (4h15m) and comparable to driving the distance in your own car (3h55m if you stick to the speed limits)
I'd much rather take rail relative to the alternatives even if it takes longer and maybe costs more (especially leaving aside parking). And many others do as well even if it would be faster to drive.
And generally Manhattan is pretty walkable once you're there.
York to London is 215m and 2 hours, along a line that’s nearly 200 years old. Paris ti Lyon is 290 miles and takes 2 hours on a 40 year old track.
[1] https://www.sncf-connect.com/app/en-en/home/shop/results/out...
Those things are true, but like, jeez, the price. I for one don't even mind Amtrak's slow speed on its own, but not when it's more expensive than faster options!