Pounds Mass vs. Force
Things change slowly, but the advantages of SI system are so significant that it seems odd that the US is still holding out. We changed to SI in Australia 30 years ago & people complained about it for 20 years but imperial is still hanging on. Everyone seems to know their height in feet & inches, but not metric. Everyone knows a tall man is 6' & a small woman is 5' & who knows the metric equivalent. People often estimate in imperial, but measure in metric - even people who are too young to have been taught imperial units just use feet and inches as the standard for approximating.