Your analogy is one indirection from being a fit. Factories usually get custom solutions for their production facilities, tailor made by specialist engineers. They then run the production and deliver mass produced goods to the markets. We software engineers aren’t delivering tailor made solutions straight to the consumer markets. We are much more like the engineers who set up the machinery in the production facility, and our software is much closer to that machinery then it is to the mass produced table you buy at Ikea.