The point is that for most things, there were no such off-the-shelf parts in software engineering until recently. You had to invent each screw and bearing yourself, because you couldn't just order a bunch of screws and bearings. Nobody sold them.
Moreover, the difference is that today's technician-programmers don't know how screws and bearings work at all. The engineer who uses prefab screws and bearings still understands them in detail and knows when to deploy them and when not to. Rather than understanding what bearings are for, the technician-programmer has a problem X, reads a blog post that says, "I solved Y by adding some bearings," and thinks, "gee, X is similar enough to Y that adding some bearings may work."
They add some random bearings, some screws, some cams and driveshafts here and there, without any deep understanding at all of why you ought to use these things in a design... and over time build a Rube Goldberg monolith with 10,000 moving parts sticking out randomly that nobody actually understands at all, so as a result everyone is terrified to work on any part of it for fear of inadvertently breaking the other 60 hidden dependencies of that piece.
Moreover, the difference is that today's technician-programmers don't know how screws and bearings work at all. The engineer who uses prefab screws and bearings still understands them in detail and knows when to deploy them and when not to. Rather than understanding what bearings are for, the technician-programmer has a problem X, reads a blog post that says, "I solved Y by adding some bearings," and thinks, "gee, X is similar enough to Y that adding some bearings may work."
They add some random bearings, some screws, some cams and driveshafts here and there, without any deep understanding at all of why you ought to use these things in a design... and over time build a Rube Goldberg monolith with 10,000 moving parts sticking out randomly that nobody actually understands at all, so as a result everyone is terrified to work on any part of it for fear of inadvertently breaking the other 60 hidden dependencies of that piece.