Quite. We’re far more similar to construction workers than we are civil engineers, despite the lofty title we like to bestow upon ourselves.

And from slightly different view. What we make is not output of modern mass production. With highly tuned and most of time perfectly matching parts build into one unit.

Instead we make pre-mass production bespoke products where each part is slightly filled and fitted together from bunch of random components. Say the barrel can't be changed between two different handguns. We just have magic technology to replicate the single gun multiple times. Does not mean it is actually mass-produced in sense say our current power tools are.