They do have indoor assembly line welding robots. But, they don't have welding robots for outdoor, ground-breaking construction job sites yet.
I mean, do they?
We're not far off having adaptive autonomous pipe welding in-situ.
https://www.thefabricator.com/thefabricator/article/tubepipe...
China isn't that cheap anymore either. They have machine tooling and economies of scale.
The US is basically in a cold war with China since they are now the principle global rival.
China's population is set to decline by a massive amount from one child policy. This combined with other supposed economic boondoggles will collapse the system.
The world learned that ultra extended supply lines aren't a good thing in COVID, and the world just seems to be going to a more chaotic era with likely lots of wars over resources, population displacement from global warming, and lots of other not-fun stuff.
Finally, the United States is becoming more isolationist. With the shrinking geopolitical importance of oil, the US might stop enforcing Pax Americana on the high seas. The primary function of the navy was to secure petroleum, and now with EVs, alt energy, and the Bakken Shale we don't need to do that for us, or the rest of the world.
So... take your pick
AI LLMs can't weld.