Customers coming up with it is basically fine*, but it's also why the SpaceX IPO chose to use "TAM" as a big number to dangle before investors: if you can do the work of {$6T + markup}/year worth of desk jobs, that's your customers.

However, customers coming up with the money is the easy half of the problem. The hard part is having them pay you.

Wikipedia's valuation is on the small side of {number of people on the internet worldwide} * {peak price of Encyclopaedia Britannica} † despite containing a lot more content.

LLMs can only chase high margins while they're ahead of their competitors; the moment the investment stalls, open weighs catch up, they loose their edge. Cloud compute providers still win on supplying inference, but there too competition will likely lower margins, not justify huge valuations.

NVIDIA may remain as valuable as today, but their P/E ratio will likely shrink a lot even while keeping up the price.

Model makers still have a problem here even if the tech is so useful it rapidly grows the economy: "free" is right behind them almost immediately after they stop.

* under the assumption the tech is real; there's plenty of people here on Hacker News who still dismiss it as a "scam"

† that would be about 13 trillion USD, from what I read