Truth is, Essential simply had no chance. The segment of users caring about build materials and craftsmanship is also the one who care about stuff like camera quality, software quality and features and when the PH-1 launched, its camera sucked, it had less features than other flagships and it was riddled with cellular reception issues. Price wasn't cheap either.
If it wasn't for Andy Rubin, there's no way this startup would have received the investment they did.
At this point Samsung's phones are about as American as Google's or Apple's.
With all that said, it might be worth considering that recent events at Essential suggest that this might not be the significant competitive edge that might be hoped for. It's abstractly possible that our tastes in phones might not be an accurate reflection of the wider market.
In another sense, the ownership of Samsung is irrelevant. The actual phones have roughly the same level of US-origin content and US-local labor as those phones famously labeled "Designed by Apple in California".
Essential or anyone needs some innovative new features or 'feel' to it.