Most of the young generation have adapted themselves to using the metric system of measurement that if you ask them to quote it in the imperial system, they are quite blank. The same happens to me when I am asked to say measurements in centimetres rather than inches. That was the way my generation was brought up and I find it very difficult to change.
Of course the metric system is more precise as it is broken down into more parts. For example in school we were taught that there are 8 parts in an inch. So if the measurement is smaller than an inch, we will say 1/8 inch or 3/8 of an inch. If it is smaller than one part, we say, 1/16 of an inch which means half the size of one part in that one inch. The smaller it gets. the more confusing it becomes.
The metric system simplifies that because it is broken into many more parts. For example an inch is approximately 2.5 cm. and in one cm there are 10 mm. So within that 1 inch, there are 25 parts instead of the usual 8 if it is measured in inches. So you can see, it makes measurement a lot more accurate. The way that measurement is denoted is also very much simpler. We just simple say 1 mm or 3 mm. There is no need for confusing fractions.
Having said that, the majority of contractors still uses the old system when doing their work and many materials used in the construction sector still follows the old system for the benefit of these contractors most whom are not very highly educated. The length of nails are still denoted in inches. No contractor will understand you if you say you want a 5 cm nail, but they can tell you which is a 2 inch nail by just looking at it. All measuring tapes used by contractors shows 2 readings. In mm and in inch. Those who are higher educated will rely on the metric system as they were taught to use that in school.