At some point someone invented the router to cut wood. I have one in my shop and it has yet to produce a beautiful ornate window.

Like a router, an llm is just a tool. the problem is that llms report back to their masters. They also know too little about your specific problem. And they're not good at math or engineering, they just guess. So you have to craft your questions carefully and around things you know so you can fact check. Otherwise they're awesome.