It's shocking/hilarious how much/many people believe that there are any economic prospects in generative AI. By definition, if something is generated by an AI then it's worthless if for no other reason than supply and demand. There's also a reason it's called a singularity, it sucks everything in that touches it but otherwise has very little influence on anything else.
Have you tried talking to Siri? Compare that to ChatGPT and you'll see that it's much better. The predictive nature of LLMs are perfect for voice assistant use cases, which when connected to "plugins" means we'll all have our own personal assistants. That's worth something.
But people in general don't seem to be interested in voice assistants in general. They were a huge hype when you basically had to manually uncheck boxes to not accidentially order an Amazon Echo, etc, but as quick as the hype was there it was gone. To my knowledge Amazon has yet to make any kind of substantial revenue with Alexa stuff.
With LLMs I would expect this to be even more of an issue given how costly the inferencing alone is when we're talking about an LLM. And yes, the utility will likely increase substantially with the adoption of LLMs as opposed to previous language processing techniques, but I don't think this will outweigh the disinterest in the overall technology.