Never gonna happen.
Back in the ‘70’s, my college-educated sister tried to extol the virtues of the metric system to our farmland aunts and uncles.
Needless to say, it did NOT go well for her. I finally had to change the subject to animal husbandry or some such more relevant topic.
“Never gonna happen.”
It should, and it probably will.
The reason is the ease of most calculations. For instance, if I ask how much 500 cubic feet of water weighs, you’re going to have to go through some contortions to figure it out.
On the other hand, if you ask how much 500 cubic decimeters of water weighs, the answer is instantly known - 500 kg (a cubic decimeter is also one liter). For 500 cubic meters of water, the answer is 500 metric tons. Since density is expressed in terms of water, answers are equally easy for other materials.
The ease of calculation is the same regardless of the type of unit, which is why metric is the standard in science and engineering.
Switching to metric would also eliminate a ton of barriers to trade, both import and export.
It’s getting to the point where the cost of retooling is outweighed by the advantages.
When I was a child 40 years ago Scientific American was a great publication. Some of the articles I had difficulty understanding because of my age but I tried and I learned things that surprised my teachers. About 1980 things changed. Scientific America became much more agenda driven.
I canceled my subscription. If is difficult to see an old friend die before your eyes and become a zombie.
I remember being told in fifth grade that we had to learn the metric system because everything in the U.S. was going to shift over. That was a long time ago and the only time I remember it really being pushed on us was at the gas pumps, how did that work out?