I think part of this was that in the past, computers and software were new and novel. People had no comparative experience, so training had to be provided to fully explain what you could do & how you could do it.

Compare to today where most people "learn" by immersion - you have to use Google Docs or Excel for your school work, so you adsorb just enough to get your work done without really understanding the fundamentals or the more complex or non-obvious features, since you weren't taught systematically or comprehensively.

Then you "know" Excel, or Word well enough to get by - but don't know that you are barely scratching the surface of it's capabilities, or don't realize that being more competent with the tool will make you more capable and productive. And thus the motivation/opportunity isn't there to invest that time and effort.