Some thoughts/things spring to mind.
I have seen woodworkers fettle/adjust their tools and talk in the order of thou (Americans on youtube or TV).
They they build with wood. If it rains outside the table get bigger, and wood will marginally twist, cup, and bow, but by more than a few thou.
I have digital calipers, but usually only read them to the nearest 0.5mm. I just use it for quick sizing of hardware and components.
Imperial measurements are only used in the US as far as I am aware. What is the point of teaching European school kids about a system of measurements that they will never use. Except perhaps in a social history lesson.
Why teach high school students to read vernier scales, if it is unlikely that they will ever use them. Those who do go on to university to study engineering can learn it there, if the course designers perceive that the needs of graduate engineers includes it. It is better to fill the high school curriculum with things that are more relevant to today's world.
being of a certain age, I was taught both metric and imperial. large areas are done in fett, small in mm in my world.
for 30 years I worked in the print trade, using mm,grams,microns, picas ens, ems and quads etc.
After being made redundant last year, I retrained as a wind tunnel operator, having to learn barometric readings, measuring in ft/sec, bar, psi and believe it or not ft and inches, as a lot of equipment used is american!! so having to relearn all the threads for bolts again!! Fortunatly, my late father was a template maker at Vauxhall, and after he died I inherited all his tools. I never opened the tool boxes up after he died, but last year I did, in one box was a load of books that he used to use to teach the apprentices all about the different threads used in engineering in the 1950's to the early 70's. no mention of the metric system but a lovely big section on the american system which i now use, plus all the tools that i will ever need, including trig tables and 2 lovely slide rules, old vernier gauges ba/uncf spanners taps and dies, height gauges, french curves, protractors old berol markers(the really stinky ones you get high on!) engineers blue, modified cone drills etc. An alladins cave of tools and info. Thanks Dad, never thought I would look at them again, let alone use them!