What if it never pans out is there infrastructure or other ancillary tech that society could benefit from?
For example all the science behind the LHC, or bigger and better telescopes: we might never find the theory of everything but the tech that goes into space travel, the science of storing and processing all that data, better optics etc etc are all useful tech
And we already seeing a ton of value in LLMs. There are lots of companies that are making great use of LLMs and providing a ton of value. One just launched today in fact: https://www.paradigmai.com/ (I'm an investor in that). There are many others (some of which I've also invested in).
I too am not rich enough to invest in the foundational models, so I do the next best thing and invest in companies that are taking advantage of the intermediate outputs.
In fact I would say that one of the things that goes to values near zero would be land if AGI exists.