I'm not sure about your general point - people definitely use more things as they become cheaper, which is a good thing IMO, but you're right that this means power consumption doesn't necessarily go down with lowering costs.
But just to add another dimension to the discussion, there's an interesting book I've heard about, the thesis of which is basically that technology has made a lot of material goods much more efficient. E.g. they give the example of aluminum soda cans - nowadays, the cans themselves use much less material than 50 years ago - using modern production technology, using CAD systems to design them better, etc. has led to a lot less material wastage (I think it was like 25% or something like that, but I'm not sure).
And in general, from the point of view of the companies selling material goods, the less material and more efficiently produced materials the better, since that's a direct cost, meaning they are in general working to make everything a lot more efficient.
But just to add another dimension to the discussion, there's an interesting book I've heard about, the thesis of which is basically that technology has made a lot of material goods much more efficient. E.g. they give the example of aluminum soda cans - nowadays, the cans themselves use much less material than 50 years ago - using modern production technology, using CAD systems to design them better, etc. has led to a lot less material wastage (I think it was like 25% or something like that, but I'm not sure).
And in general, from the point of view of the companies selling material goods, the less material and more efficiently produced materials the better, since that's a direct cost, meaning they are in general working to make everything a lot more efficient.