I would phrase what you're saying differently. You can pay down cognitive debt by incrementally simplifying a system, or by throwing it out and rewriting. You're just describing the standard decision between rewriting or fixing in place. Joel Spolsky famously argued against rewriting in nearly any situation, but AI changes the argument. (As does the much higher starting point of open source libraries and systems and frameworks usable for many things; it's been awhile since he made the argument.)