LLMs are good at language processing tasks. Asking it to write code or solve complex maths it will make things up. Plus, it takes large amounts of energy to run them. Not to mention the data needed to train them.

Code written by them always has security holes. Use it to find facts, correct grammer or maybe generate a small paragraph or essay. But, don't use it to generate code, medical device, etc.

As a recent example Chatgpt cannot answer if there is a seahorse emoji. It will get infinitely stuck in trying to be funny and finding an answer. Changing the answer mid token.