Nicely described personas! I hope Devin is not sharpening his skills in a random way though. The secret is do a right mix of learning by practice, applying and devising theories, deepen understanding, reading beautiful code, trying to express yourself clearly, exchange ideas with others. It's not about memorizing particular libraries or frameworks, which does not provide the same non-linear productivity boost as recognizing patterns, "compacting" them into learned or own theories. In other words, developed abstraction skills is probably one of the most influential productivity factors.

Instead of doing things like

((2+2) + (2+2)) + ((2+2) + (2+2))

one can have fun and gradually learn to express it like

2^4

Fundamental topics in math and computer science can give you some advantage, but it's the way of thinking they suggest, that can make you not only productive, but also have much more fun in the process.

In other words, quantity and quality in learning are related (one with a lot of experience will necessarily start to classify all that knowledge), but organizing the learning process itself can bring results faster. Those with growth mindset probably also learn this trick early.