Again, I'm sure it's best to use both. Where I tend to step on my own feet is when I hafta admit that learning to "read" is probably ten times harder after one's become a more or less proficient ear player, cuz an ear player already knows where the next note is on a familiar piece, and since most ear players tend to "learn" the notes after hearing it once, he /she already knows the verse, chorus, whatever after hearing it once, and the chart becomes a distraction rather than a help.
You're right. Surprised? (mostly right)
Being a reader makes me lazy. i don't have to memorize,'cause it's all right there in front of me. I've always
envied admired ear players their ability to absorb music nearly instantly.
~however~
There is a difference between knowing what the notes on the page mean, and sight-reading fluently with few mistakes on the first try. The same with listening to a recording multiple times, and still having to guess what the notes are, and hearing a recording once and duplicating it flawlessly on the first try.
It's a matter of degree, and of cracking the code. Which is why most kids don't pursue music as a career, or even as a continuing hobby. Without the passion, other things become more important. Cars. Painting. Dating. Math. Sports. College studies. Military.
With music, as with anything else, there is more than one way to (pardon the image) skin the cat.
Adult learners have other challenges. Essentially, a brain crammed with a whole lot more stuff than a 10 year old's. And unrealistic expectations that being smarter than they were as a kid that they'll learn more easily. "Patience, grasshopper."
Tom