A woodworking example is that a planer is great tool that helps you make nice flat surfaces. But, to a certain extent, it's a downstream fix that wouldn't be necessary if a carpenter was using a better overall process. I.e., if their upstream process for cutting/ripping wood made nice flat surfaces to begin with, the awesomeness of the planer becomes moot. (Apologies to the legitimate woodworkers if this analogy is off).
Where tools like GPT becomes invaluable is when you have no control over those upstream processes but still need to get the job done. But leveraging a tool for a downstream fix when upstream fixes are possible is usually a less-good approach to creating good systems.