Why believe that, if energy is always conserved, that some activity or motion must always be? Why can’t energy be simply latent? Isn’t some energy potential?
Distinguish the potential or latent into the counterfactual and the actual. To explain: wood in a world with no oxygen would be counterfactually flammable, but not actually flammable. In the same way, potential energy in a world with no actual motions to serve as trigger events would be counterfactually potential, but not actually potential. But potential or latent energy cannot be merely counterfactually potential, as we have to be able to locate it in a causal series of actual forms of energy. The conservation of energy in the real world can’t be established by conservation in a counterfactual world. This commits us to a world with actual trigger events, i.e. a world where real motions and activity are not just possible, but necessary.
For example, if you say a coin has real purchasing power, you’re committed to the idea that there is some actual population that accepts it. Minae, shekels, lire and Deutsche marks have only a counterfactual purchasing power, and so one can’t convert from actual currency into them. But it is precisely just this sort of conversion that allows for conversion laws.