I think the idiot-proofing of modern computing is only making people less aware of how computers work. Think of how many 20-something programmers got into programming from learning how to make Minecraft mods. Or even just learning to install a mod in the old Java version of Minecraft or any other PC game, where you had to dig into weirdly-named folders, copy-paste files into various directories, maybe modify a data file here and there. Kids growing up on the iPhone version of Minecraft are never being exposed to the basics of how their device works.
https://www.theverge.com/22684730/students-file-folder-direc...
That being said, we've always built knowledge on top of the backs of others and never really had to deal with supporting its weight without necessarily knowing the basics. It would really make for an interesting case study if it led to the collapse of society.
I don't think it's this, and I don't think programming is so hard (it's the business logic that is hard when you have to specify it exactingly, to reference the thread.) I think that the manufacturers of the various computers we use make it unbelievably difficult and scary to touch anything, and cast quite a bit of suspicion on you for even wanting to change anything.
I feel like we actively discourage people from having an understanding of technology for fear that they will understand it and complain about it and/or be in a better position to judge the quality of alternatives to our products. As a result, it seems like more people understood basic computer operation and architecture 30 years ago than they do today, but maybe I'm in a weird bubble. I'd think with the opportunities for the far more opaque operations and algorithms that deep learning has given us, people will understand even less about computers in the future.