We always were the only people who ever knew how it worked. In 1990 people fellow students called me to fix their computer, they had absolutely no idea how any of this worked. No. Idea. Yes, the machine was being difficult; but their reaction wasn't to fight it, or understand it. It was to call someone to do it in their stead.
I'm not sure things are very different now.
I feel that things are pretty different. Although the example of interrupts and jumper settings being common knowledge is a bit of a stretch... it's still amazing to recall that MS-DOS was regarded as an end-user / consumer OS, and that, more generally, it really was regarded as totally normal to need to invest some time in learning about the system, files, directories, typing, configuring/customizing settings and network options just to be able to do what you wanted to do.
I find the current expectations around consumer "apps" to be totally infantile in comparison, where everything is now a single-purpose "app" that does exactly one thing when you push a button, and if you want something even a tiny bit different.. you can't, and that even basic things like files and settings are no longer accessible.
Maybe the difference is more of the professionals in the field now haven't built that same muscle, as there's a broader group of people working in tech. Whereas the folks that could fix things in the 90s mainly gravitated to computers as a profession. Just random musing though I truly don't now.