In China (put aside all the political issues at the moment), they were building elevated track to the tune of something like a mile a day at the peak. (On the order of that magnitude -- elevated! Not even just plain track on bare earth)
What does that produce? A rail-building skilled workforce (10,000+ engineers) that has lots of practice, expertise, and templates to stamp out that stuff like it's their business. Here, we do this now, what, once per decade? Are there even 1000 such engineers that US companies could muster together to work on a project, not even to speak of the necessary contributing industries supplying the specialized tooling, materials, expertise for such a project?
I realize the story in question here was about a road bridge, but still it involves coordination and management with the rail component, and the point still stands I think.
Industry-wide skills and personnel fade and atrophy when a country doesn't do these things any more, or go overseas to where there are projects for them. These generational shifts in capabilities happen, unfortunately, while a country is not looking.