Earlier quoted context omitted.
I think time well spent is a huge factor to anyone success. Most pro athletes, chess champions, musicians, artists, etc, picked up their hobby at a young age in most cases, and just stuck with it until adulthood and enjoyed the compound effects of having a teacher or coach spend time with you multiple times a week for decades. I think you can put anyone in that environment and they would become elite in whatever you…
No, some people are so stupid that they will never be able to do tasks much more complicated than e.g. sweeping the floor. You are trying to conjure a vision of the world that is comfortable to believe, but that vision does not reflect reality.
To me, 'everyone' does not mean literally every person but rather the vast majority. Whether this number is 95% or 90% is going to be interpreted differently. I think nearly all of us can agree that as intelligence falls on a bell curve there will always be those unfortunate enough to not be able to do certain tasks. However the nature of the bell curve does mean that around 90% of people are above ~80 IQ.