> And air conditioners have had pretty stable efficiency;

I mean not really.

Old aircon was off/on which mean that at temperatures near the target efficiency drops. (as in turning on for a few minutes, it takes a while to move the settle heat around)

Moving from fixed speed ac motors to "inverter driven" (brushless motors) means that AC can be run at a speed other than 100% or 0%. Yes, CoP hasn't increased 6x, but newer aircons have higher CoP over a wider range of temperatures.

moving from Plasma TVs to LED/oled is about a 2-3x improvement in efficiency.

Laptops are anywhere between 2 and 10x less power than desktop (caveats apply)

then double glazing has a large effect on heat rejection/storage. Non-coated glass lets in something like 1kw/m2 of heat, coated glass can reject anywhere up to 70% of that.