"Noob gains" doesn't have anything to do with setting goals or quantitatively measuring progress. It refers to the speed at which unadapted athletes are able to progress (e.g. add weight to the bar, run farther) each workout when they first start training, compared to athletes who have been training longer, are more adapted, and progress slower.

Most professional and highly adapted athletes are extremely quantitative about their training programs, much more so at the advanced stages than in the early stages. They just progress much slower because it takes more training for their bodies to continue adapting.

"Noob gains" just means that new quantitative measurements can take place over a short period.

Athletics is incredibly quantitative- even for the most advanced and experienced athletes.