Imagine a drug that cures Alzheimer's. Does that improve the baseline cognitive level of the population? What about if we manage to find a cure for various intellectual disabilities (Down's, Fragile X, FAS, etc.). Does that improve the baseline cognitive level of the population? What if we mitigate some of the worst effects of aging on a population wide scale?

What if we achieve an understanding of how memories form in the brain and what factors distinguish individuals who have eidetic or near eidetic memory and can synthesize drugs or treatments that replicate that? What if we can find similar distinguishing factors for other cognitive domains (perception, visual spatial skills, etc.) and find drugs or treatments that improve those capabilities?

> but the opening sentence seems to suggest the cure to smartphones and AI having significant negative impacts on critical educational development is giving all kids pharmaceuticals.

You have to be operating extremely cynically for that to be your default interpretation of what I said, but go off.