You can do this in practically every EU country, not to mention Asia (I don't know about other parts of the globe) via trains. I don't get why it has to be a car. It's just that the US has zero infrastructure for both inter city as well as intra city public transport outside of like 4 cities.

I am an American, so lacking the ability to reverse 80 years of public policy decisions, I want the sleeper-car-car.

The US has one of the most extensive rail networks in the world. What we do differently than Europe is use the rail network almost exclusively for freight. If we followed Europe's lead and did a lot more freight via long haul truck, we could free up a bunch of infrastructure for passengers, but would the end result be a net win? Or would we actually increase emissions by doing that?

There is absolutely no reason to make that tradeoff. If a rail line is hitting maximum capacity, then that means there's plenty of money going around to expand it. Adding more passenger trains does not require decreasing the amount of freight trains. That's not the reason we're bad at doing passenger rail.

Freight rail has significantly different requirements than passenger. People want to move quickly, with frequent daily trips (eg 24 trips per day, moving at 90mph). Freight does not care about train speed so long as it is reliable (eg 1 trip per day moving at 50mph). Logistics networks can plan around reliability.

For one, pull up a satellite view and look at the US anywhere 150 miles away from the west coast.

And we have buses that go between lots of cities(greyhounds). They just suck compared to driving yourself or flying, which is why you'll pretty much only find poor and desperate people on them.

Well, it's a bit more PITA to get your ass to station with all the baggage, then also possibly changeover to another line. But yeah, to the airplane it's an altenative.