They can be useful, used "in negative". In a physics course at an institution near me, students are asked to check whether the answers to physics questions given by an LLM/GPT are correct or not, and why.
On the one hand, this puts the students with their back against the wall, so to speak, because clearly they can't use the same or another LLM/GPT to answer, or they'd be going in circles.
But on the other hand, they actually feel empowered when they catch the errors in the LLM/GPT; they really get a kick out of that :)
As a bonus, the students see for themselves that LLMs/GPTs are often grossly or subtly wrong when answering technical questions.