It actually scales by "going wider" and being able to do more things rather than iterating on the same code over and over again. If you can only write X amount of code per day because of some limitation (human attention, source control, CI, whatever it is), you would of course use that energy on the highest priority and highest value work. As we remove scaling issues in source control, for example, we can just "do more things" without worrying about bringing down infrastructure.