Technologies come and go, but often when a worldwide popular one vanishes, it's because it got replaced with something else.
So lets say we need LLM's to go away. What should that be? Impossible to answer, I know, but that's what it would take.
We cant even get rid of Facebook and Twitter.
BUT that being said. LLMs will be 100x more efficient at some point - like any other new technology. We are just not there yet.