Looks very superficial. There is an implicit assumption that developer skill is scalar and transitive. If Alice is better than Bob, then Alice is better than B

Looks very superficial. There is an implicit assumption that developer skill is scalar and transitive. If Alice is better than Bob, then Alice is better than Bob at everything. If Alice is better than Bob, and Bob is better than Charlie, then Alice is better than Charlie. This may be true in a narrow niche or for a specific skill, but does not hold in general. Then there's little to substantiate the claim that "Simply deciding to become a 10x developer will give you a huge advantage over the competition." Sounds like a slogan from the self-help section of a book store.