As a former draftsman: this is not accurate. You might think that units are convertible and we have plenty of software for that. But it doesn't work that way.

As a former draftsman: this is not accurate. You might think that units are convertible and we have plenty of software for that. But it doesn't work that way. If a drawing says to drill 3mm holes and you have imperial drills, what to do? If a drawing says tolerance is 1/64 inch, how do you use your metric digital calipers quickly to verify it? If you have a paper drawing provided to you, which is the reality of life in the field, how do you visualize all the dimensions in your head if they are in a system of units you don't use every day? If you receive a part with 28mm wrench flats, how can you be sure they aren't meant for a 1 1/8 spanner? There are real mass produced parts where the metric female threads can easily be enlarged (or stripped!) to accept imperial male threads. But the converse doesn't work, and even if you possess a tap you probably don't have a metric thread gauge in your imperial shop. It goes on and on. Software won't eat this problem, so we have to.