I'd also be surprised if it's like oil. But…
> I don't see how a chatbot meets any of those criteria
Calling these things "a chatbot" is likely limiting your vision: some of the stuff people build by fine-tuning LLMs, such as the ones OpenAI offer, use them to generate database queries matching their customers' database schemas.
"Chatbot" is simply a convenient UI for an LLM in the same way that a web browser is a conventional UI for email. (And in this analogy, anyone calling an LLM "autocomplete on steroids" would be making the same mistake as someone saying "Wikipedia is just TCP on steroids").
I expect LLMs to continue to be extremely generic in the same way that web browsers are (market history shows periods where one browser dominates the market despite open source) or like spreadsheets (where Microsoft Office is, or was last I looked, dominant despite free offerings being good enough for most people).
Society needs intelligence. We started using mechanical aids because it became impractical to perform census work by hand as the population increased, AI is a continuation of this process: we need it, it's a commodity, there may be a market opportunity despite free and/or open source competition, and (like Netscape, like Internet Explorer) there's no guarantee that the winner in one year will still be leading the next year or even existing a decade later.