"Which hasn't struck me as particularly advanced either"
Are you sure? Moving long and heavy trains has its own issues - you need specifically designed engines, often multiple engines that can work together, and some are even designed to cope with the quirks of specific lines. They may not look sleek and shiny like passenger high-speed trains, but they require their own technology.
It's very different than running light high-speed trains on their own carefully laid down lines which avoids smaller radius curves and slopes beyond very strict parameters, and usually run across densely populated areas.
The Chinese "Belt and Road" project requires to haul a lot of goods by train across China and a lot of Asian and African countries which may have old long lines running across little populated and difficult terrain, and may not be (yet) electrified - not surprisingly not very different from a lot of US territory crossed by freight trains - where it could be too expensive to deploy and run anything close to high-speed electric trains.
US train makers have a long experience in such kind of transport, you won't see it for example in Europe where routes are shorter and most of it electrified, for example.
Biting the hand that feeds IT
