What are the obvious tells? List them, because I think our sense of the tells may not overlap.
This article is clearly LLM-generated, even the title. A key indicator is that it almost makes sense: we forgot how to manufacture because that got sent to a different nation. The coding thing isn’t getting sent anywhere, so humanity is forgetting how to code. The distinction undermines a lot of the emotional baggage about offshoring that the article wants you to bring along.
There are quite a lot of them: https://en.wikipedia.org/wiki/Wikipedia:Signs_of_AI_writing
But it's really just the usual ones that are truly obvious. "Not X but Y," em-dashes, "underscores the significance of X," and so forth.
A terse sentence structure can be a tell, but, IMO, it's a weak one.