Trains in the Americas are kinda crap.
In South America and Central America, the terrain is mostly too mountainous for an efficient rail network. However, the US was built on the backs of railroads, so what gives?

The main thing that makes passenger rail inefficient is, ironically, freight rail, with the illegal prioritization of their freight trains over Amtrak's passenger trains.  Freight rail drops Amtrak's on-time rate from about 99.75% to about 72%! There are a few other factors that are more systemic. One of these is that Amtrak is technically a for-profit company. This is absurd, as they never make a profit, and Amtrak is almost always just paid for by taxpayers, so what reasons does the government have to not take control of the company? This would give them the benefits of improved policing powers, greater funding, and less concern over losing money.