Sebastian Marshall is on my side with feedback and practice. Read it. He (and I) disagree with the WSJ article here. FWIW, There is a major factor that none of the folks are paying attention to.
Returning to the Aretaevian theory of learning/expertise...
90% of learning is motivation (active/eager engagement)
9% is practice
1% is other stuff -- Talent, etc.
When everyone has similar motivation and practice, then talent takes over...and until everyone has reached the same levels of practice and motivation, talent is halfway to irrelevant...at least for folks in the first 4-sigma above average.
What is missing from the discussion is a quality-of-practice issue...Practice is part quantity and part quality. Shooting 1 million baskets does not make you a basketball star...but it is very likely to make you able to hit the basket when you shoot (without pressure, from at least most of the places on the court where you practiced). On the other hand, if you're throwing those baskets up underhanded, around the back, and goofing about, even 1M baskets shot won't necessarily make you a good shooter. What makes you a good shooter is the adjustment on shot 2 after shot 1 misses...and the attempt to recreate shot 2 with shot 3 if shot 2 goes in.
On the other hand...your chances of being a basketball expert if you haven't taken the couple hundred thousand shots required is near zero. Practice is necessary, even if not sufficient.
Similarly, Arithmetic expertise is not gained by just getting a math worksheet with 300 problems, and writing something down every day for 10 years (300+ 365*10 ~= 1M) Arithmetic expertise is gained by working on improvements in speed, and dealing with the feedback. If you write 7*8=54, and never get it checked, you're making yourself LESS good at math.
On the other hand, if you don't have addition/multiplication math facts in your head for instant recall, you can barely learn fractions because you have too many steps to think about. Proper fractions analysis is: What is 1/2 + 2/3 ... well, thats 3/6+4/6 = 7/6 = 1 1/6...if you pause to ask what's 2*3 or 3+4...you cannot do fractions...and you certainly can't use fractions for anything that takes cognitive effort.
On the gripping hand, if you do your 1M problems of arithmetic...that still doesn't make you good at Algebra (though you're MUCH MUCH better prepared).
Practice: Quantity, Topic, and Feedback are all huge. Insufficient attention to any of those and you won't get good at whatever you're trying to learn or become good at.
Hypothesis...IQ allows you to better self-manage your next steps...but almost never as well as a coach could.