This has more to do with how commuter trains are forced to give priority to freight trains, causing delays, than actual travel times

It's not that extreme, but even if we assume a 200 mph HSR train:

• It would still take 12 hours to drive the 2500 miles from Los Angeles (California) to Jacksonville (Florida)
• It would still take 6 hours to drive the 1200 miles from Jacksonville (Florida) to Boston (Massachusetts)

Admittedly, there's a point to be made that hardly anyone would drive from Florida straight to Massachusetts or the other way around, but the distance is still impressive.

Airplanes who fly at 600 mph reduce that travel time to 1/3rd (excluding boarding, which can be time-consuming). I did not calculate how much a train ticket would cost, compared to a flight ticket.

Admittedly, i travel 400 miles by train in Europe all the time. (a couple times every year). It takes about 6 hours in total.

If you go 300km/h by train and 900km/h by plane then the numbers don't add up.