If engineering isn't near the factory, it's not as effective. Here's one of the most generic electronic components - a 1K resistor.[1] These sell for about US$0.0015 each. DigiKey has a list of many suppliers. There are a few old-line US resistor makers in there, including Bourns and Ohmite. They're price competitive with Chinese companies. But when you look up their engineering job locations, none are in the US or U…
In general though it seems where design/codehardware feedback loop needs to be very fast in some cases, it is a non trivial separation of concerns.