I’d argue the two greatest barriers for the average, non-STEM individual adopting metric in America is the speed limits being in mph and the temperature being in °F. Both are convertible easily enough, but when you constantly have to do so to engage with critical infrastructure or safety (cooking temps, etc.) It provides a barrier against adoption for anyone without the drive to make a concerted effort to use metric.
I’d argue the two greatest barriers for the average, non-STEM individual adopting metric in America is the speed limits being in mph and the temperature being in °F. Both are convertible easily enough, but when you constantly have to do so to engage with critical infrastructure or safety (cooking temps, etc.) It provides a barrier against adoption for anyone without the drive to make a concerted effort to use metric.