The country has made great progress in terms of fuel economy. But the most popular vehicles sold in the USA (full sized pickups) still get like 18MPG. The majority of efficiency gains go into making them larger and more powerful, because there's no economic incentives to make trucks with the size and capability of 90s era trucks, but with double+ the fuel economy. Ford was at least able to be forward-looking and release the Maverick, a small hybrid pickup, at exactly the right time.