LIRR is NY MTA, they sort of merged all of the regional rail in the state into the MTA umbrella. The other regional rail line is Metro North, servicing upstate NY. NJ has both PATH for commuter trains, and NJ Transit for regional rail. And Philly is all SEPTA. They’re all interconnected to one an other via transfer at major hubs or borders. And a similar sorts of systems can take you further. I’m just not familiar with the lines. And there are a lot more runs on all of these in a day than via AMTrak.
You can in fact get a lot further, and to a lot more places via these regional rail lines. I used to do it all the time from Eastern LI down to Philly. It is slightly less convenient than AMTrak, in that you need to transfer multiple times and purchase multiple tickets. But its often just as fast, and critically its cheaper. AMTrak you still need to drive or take regional rail to get to or from the AMTrak stations. Which tend to be only in major central hubs along the route and in the cities its intended to service. So as its stands its just sort of a slightly faster (as in minutes) and much more expensive middle leg for your rail journey.
The other critical thing about regional rail in the US is that it still sucks. Just like AMTrak they run outdated, dirty, slow trains on antique track. They’re often just as unreliable. And service to outlying areas is routinely cut. My town currently gets 2 commuter trains a day. They head all the way out. Then turn around and return to NYC. So you get 4 opportunities to actually physically get on a train. Unless its a holiday or a weekend. There are variably no trains or one train on those days. So functionally we still have to drive to a hub station to use the train, and the train is useless for anything but getting in an out of the city. Shuttle bus services pick up in every town, cost less, and gets you there faster (fewer stops).
The reasons for this are basically the same reason AMTrak is a failure. As an example the MTA is a very similar pseudo-private transit company. And they are like wise constantly broke, constantly raising rates, and perpetually unable to provide improvements or maintain the volume of service that already exists. All while taking decades to complete new construction or projects. Which are already outdated and in need of improvement by the time they finally finish.
I don’t know. But there’s a major difference between commuter rail and regional rail in the US. Though sometimes (thinking Philly and NYC here) regional rail acts as the commuter rail. Or in NY case, is basically useless for anything but commuter use. Europe seems to always have one or two big systems covering all usage. So while the video was focusing on high speed intercity connection. That likely rolls a lot of what we might classify as commuter or regional rail into the same numbers.