Well, that depends. Very inefficient code tends to only be used when absolutely needed. If an LLM becomes ten times faster at answering simple prompts, it may very well be used a hundred times more as a result, in which case electricity use will go up, not down. Efficiency gains commonly result in doing way more with more, not more with less.

Correct. This is also known as a rebound effect [1], or, specifically with regard to technological improvements, as the Jevons paradox [2].

[1]: https://en.wikipedia.org/wiki/Rebound_effect_(conservation)

[2]: https://en.wikipedia.org/wiki/Jevons_paradox

Indeed, that is a common occurrence that called Jevons Paradox.