They can absolutely be worse.

Hallucination Prompt injection Can’t count Obsequious to a fault Trivially swayed

https://www.inc.com/ben-sherry/an-ai-ran-a-vending-machine-f...

This news (and things like it) have been all over. The fact that you decided without doing the least bit of research that “no way LLMs can be worse” displays catastrophically shortsighted judgement. Please recuse yourself from any important decisions for the foreseeable future.