

Not sure what you mean by constant, it is definitely a huge gradient, but the layout of the US vs the EU is so drastically different that at almost every level routes that are well suited to train in Europe are often overwhelmingly inefficient in the US.
Everything from building up routes between major cities to regional and local end up being too low volume to support themselves.
There is at least an argument to be made that some/many routes should be heavily subsidized long enough to allow industry and society in general grow around them, by which time they could become self supporting, but most people don’t realize just how big the US is in land compared to it’s population, and that often results in a lot of ground to cover just for relatively few people each to get to a lot of places.
Well that’s one place we can agree anyway, trial and error are very valuable tools, they just need to be weilded carefully and not considered an error too soon. That makes it risky though.
I know i come of as pessimistic, and by a lot of measures i am, but usually only in comparison to the dismissive or condescending attitudes many people seem to have on the subject. Just build trains, duh… They work here, just do it there!
The backlash to poorly thought it arguments are usually people doubling down on their argument in the other direction, so I’d prefer to temper optimism and encourage actual conversation. Even if i may have trouble with that second part :)