I've never been to Asia, but I'd love to go to Japan. That's been a long time dream. One of my brothers went there. The trains there, he said, are always precise down to the second like the Germans. Australia (another place I want to go) is also frequently on time with their rail. Then there's Amtrak lol. We really should improve our rail system in the US.
I've never been to Spain... but I've been to Oklahoma.
The thing about Europe and Japan, for instance, is that their Govt. has dictated dedicated passenger rail tracks across the country. A lot of their freight is shipped over their highways.
America has a rail freight network that is the envy of the world.
That freight rail network shares it track with Amtrak. And the RR companies don't really want to inconvenience themselves to prioritize Amtrak.
Some Amtrak rail lines are theirs, as in the Northeast.
After the Interstate Highway System, and the air travel boom that began in the late 50's in America, it was the railroad companies wanting to dump their passenger service and only do freight, that led to the creation of Amtrak in the first place.
America spends many billions on highways and airports. Passenger rail is a very low priority, except for the NE Corridor. I doubt that you will ever see a dedicated passenger rail network across America. If you want that, you'd just have to line in Japan, or Europe.