The vast majority of organizations in the US already use the metric system in places where the metric system makes sense. Basically everyone who wants to use it is already using it.

For everything else, what's the point in the government mandating it? There's no political desire for it because society in general doesn't care, and society doesn't care because the costs outweigh the benefits. There's no practical advantage to the average person to learn their height in meters instead of inches and feet, or to have to start shopping for hectograms of food when ounces work just fine.