Their population density is much higher in their urban areas. So their train service goes from one metro area to another metro area quite well.

In the US, we use rails to move bulk commodities. In the EU, they use trains to move people between cities.

I once did a back-of-envelope calculation on what it would take to achieve the population density of Germany. Take the populations of the four most populated states of the US and move them all to Montana. Now you will have achieved a European population density. Now, put rail service between all the cities & towns in Montana. You won't need to worry about trains in California, Texas and New York state at all - because they're now empty.

Much easier job, ain't it?