I think you're using "quantitative increase" to mean "measurable improvement in output", but in the article sense it means simply "more quantity of practise" without changing the kind of practice.

Quantitative would be "I write more lines of code", "I solve more challenge problems", "I write and release more programs", "I code for more minutes each day, more days each week, more weeks in a year", "I suffer and endure more". This might get you further up in your friend group or class ranking, but won't take you to a new level (so claimed).

Quantitative changes would be things you suggest, like "I use different tools", "I approach problem solving in a new way", "I lean towards hard problems instead of retrying easy things", "I work with different people to learn new ideas", "I use languages which let me do more with less code", etc. (so claimed) those can take you to better output, even if your quantity of practice overall decreases.

We always say "practice makes perfect", but "do what winning people do" seems better advice than "do more of what you are doing, when you aren't winning". Phrased like that it's almost tautological - training longer with bad form, won't give you good form.