FWIW, what you're describing is a simple demand curve, not Jevons paradox.

The "paradox" is when an increase in efficiency which would decrease the use of a resource all else equal, instead indirectly causes more use.

Ya, are LLM's not a great example of Jevon's paradox? I don't think Jevon's needs all else being equal. The paradox being that we should be able to use things less because they are more efficient, when instead they get used more.

Surely, a large part of the increase of the demand in LLMs is in their intelligence, but to hit the demand models needed to be made more efficient, and labs found that more efficient models, still demanded more usage.