A person graduating from high school even though they are illiterate has been an issue for a long time and it is one of the main drivers behind standardized testing. I know they were complaining about 30 years ago when I was in school.
Back in the 70s the social engineers looked around and noticed people with high school diplomas do better than people without them. They didn’t like the idea that part of the reason people with diplomas did better in life was they were able to follow the rules and worked hard so they just made it easier to get a diploma. That made so much sense to them they did the same thing with college. It used to just be a problem in the soft degrees like literature and psychology but more and more I see engineering graduates who are simply not ready work in the field. They can do the computer programming side better than most of old guys but they don’t understand the basic physics of what is happening.