If we’re looking for levers to pull to help more people become advanced computer users, I believe progressive disclosure combined with design that takes advantage of natural human inclinations (association, spatial memory, etc) are much more powerful. Some of the most effective power users I’ve come across weren’t “tech people” but instead those who’d used iMac for 5-10 years doing photography or audio editing or whatever and had picked up all of the little productivity boosters scattered around the system ready for the user to discover at just the right time.
With that in mind, I think the biggest contributor to reduced computer literacy is actually the direction software design has taken in the past 10-15 years, where proper UI designers have been replaced with anybody who can cobble a mockup together in photoshop, resulting in vast amount of research being thrown out in favor of dribbble trends and vibes. The result is UI that isn’t humanist, doesn’t care to help the user grow, and is made only with looking pretty in slideshows and marketing copy in mind.