The US does have underpowered trains compared to Europe, but not the rest of the 3rd world. Given long distances to cover, no substantial passenger service (and in any case no need to make passenger service a high dispatching priority - really quite the opposite given relative hp/ton), and a corporate need to minimize expenditure (so bigger executive salaries and stock dividends can be paid), it makes no sense to do electrification for freight rail in the U.S.; there's no need for that kind of power. So what we have, except for a few confined areas where regional or commuter rail passenger service is important, is a very large-scale, efficient for its purpose 3rd-world freight rail system. With Amtrak mostly gone by the end of the year, that will be even more the case. Of course, the railroads externalize as many costs as possible - that's what businesses do if they're allowed to - with particular emphasis on those that are social in nature.

Bottom line, US freight trains don't need to be powered to the level that they are in Europe - it's a different environment, at least for the foreseeable future.