[pas]

Of course there's no free lunch, but economic equilibrium includes future obligations too (at a discounted rate), it includes the value of current unfinished things, there's a lot of real economic value backed by demand, because otherwise there's nowhere for supply to go. (Imagine if suddenly no one wants to build houses, because let's say everyone gets a tent. Suddenly there is an oversupply of construction services, and construction materials, and architects, and inspectors, and labor in general. Which will immediately triggers a drop in wages.)

You have a hypothesis about price stability, and it's easy to see that while energy prices do impact everything so do interest rates (and in general monetary policy), therefore you need a model that's more complex than what you propose.

Prices inherently aggregate almost all concerns, so even logically it cannot be simply determined by one thing (like energy). Even if energy is cheap if we misallocate it then food, housing, or transportation gets more expensive.

You seem to be mixing up monetarism with sustainability and diminishing returns.