I'm sure I'm biased by my age (mid 40s) but I think you are onto something there.
What if this constant decline in how people learn (on average) is not just a grumpy old man feeling? What if it's something real, that was smoothened out by the sheer increase of the student population between 1960 and 2010 and the improvements of tooling?
But I mean, you can get by without memorizing stuff sure, but memorizing stuff does work out your brain and does help out in the long run? Isn't it possible we've reached the cliff of "helpful" tools to the point we are atrophying enough to be worse at our jobs?
Like, reading is surely better for the brain than watching TV. But constant cable TV wasn't enough to ruin our brains. What if we've got to the point it finally is enough?