Isn't it more likely that you can catch yourself during the planning phase if the amount of work being estimated exceeds your budget? That seems much cheaper and easier to pivot from than if you were to make that realization halfway through your implementation.

> Sunk cost fallacy can be a problem if you spent sufficient time breaking down tasks for a big project. You may not want to pivot and re breakdown

Similarly, if you don't plan enough, and get far enough into a small project, you don't change your approach because of the sunk cost fallacy.