GPT-4 is far more capable than LLaMA. Just as one area of impact - captchas would become permanently ineffective. If you're experienced in developing captchas and everything they do for us, you know the implications of that alone lead to a very dystopian internet and world.
I like to answer a question with a question: if you sit and think about it, what both unintentional misuses and intentional abuses can you think of? It helps to write down a list of known abilities, then thinking up several "what if..." negative utilities or implications of each, then iterating further to see second, third, fourth order effects.