Is there any evidence for this?
Is it a definition issue?
My grandparents and some people in my parents' circle of friends are not computer-literate. And by that I mean they don't know how to use double click, what a file or browser is, or even how to use a touch focused device. They are utterly unfamiliar with the abstractions and UIs computing devices afford.
Even in my generation many kids didn't have PCs or devices with interfaces more complex than an NES until later in high school.
That is different today from what I've observed. It's true that for many the first computer is not always a PC as I would have had, but a smartphone or a tablet. But does it matter? They are able to harness the power of computing devices to get things done.
Needing to know how computers work internally, or making use of traditional computers with mice, keyboards and monitors on a desk, these things were never really the definition of "computer-literate".
Apple hides the filesystem and such but it doesn't really replace it with anything. It's not like they have some super ultra abstraction on top of it, they just straight up reduce the functionality a bit.
I don't see much critical value in understanding the things only specialists can or want to do, like how a CPU actually works or how to make an OS, but before Apple every generation had a level of abstraction they could work at that had the full power of previous levels(So long as you accept having to buy all the underlying stuff off the shelf).
Now it seems that the very newest computer users actually have less capability, because the abstraction doesn't expose the full power of the machine.
We're talking about a whole different level, people who don't even know how to effectively use what they have, troubleshoot basic issues, etc.
It's not "This is a magic box" so much as "I don't even know how to use the controls on this box and even if I could there's no button to do that thing anymore".
"I can't type or use a calculator" not just "I don't know how to divide numbers on paper"
As a french I cannot write correct english but at least I can read it. /s
Going back 20 years, I wouldve never guessed this would be the current state of affairs! As an industry we've succeeded in unlocking computing as a background enabler, but have utterly failed in making create-side computing friendly and accessible