Amtrak is still a thing for passenger trains. It’s just that it’s slower than flying and just as expensive.

This is the core reason passenger rail has not become dominant in the US. The country is so physically large that planes do passenger rail's job, but faster and at the same price point.

Instead, rail in the US is almost entirely bulk cargo as that makes a ton of sense. Cargo trains are cheaper than trucks/aircraft and the slower speed can be easily planned for.

It's not just slower than flying, it's slower than driving in most cases.

Acela is useful. We have one intercity rail line that is useful, has high ridership, is profitable, people choose to use, arguably faster than driving or flying, demand far outstrips supply. also the fastest but it’s not really fast enough to be called “high speed”

My parents once bought a private room on Amtrak. When they were shown to it, they literally thought it was a closet to store their bags not their room.