I think it's worth pointing out that education is a filtering mechanism, if a terribly inefficient one. After basic maths and literacy are learned, it imparts little on the average student. A collage degree is a proxy for a reasonable IQ and moderately high conscientiousness. Thinking of education as an inefficient filtering mechanism helps illustrate why our frenzy for more education is misguided. Certainly more eff…
But more panning in more places finds more gold does it not? Maybe I misunderstood your point. Stories like that of Jaime Escalante suggest that there's a huge number of undiscovered talent and/or that better teaching makes more talent. https://en.wikipedia.org/wiki/Jaime_Escalante
I've investigated many of the claims that one can teach intelligence. From Dual-N-Back to Head Start, they have all proven to have negligible effects on future outcomes and no effect on measured G. I think there are also pretty solid theoretical reasons to think that "learning how to learn" is not possible, as intelligence is that capacity that enables you to learn, you are strictly limited by your intelligence even when learning how to learn.
There is also increasing evidence in the literature that the theorized transfer effect (that learning one skill increases your capacity to learn other unrelated skills) does not exist.
These are not conclusions that I relish; I advocate them because I think they're true. Better a bitter truth than a sweet fiction.