That's not true in the slightest. Energy per instruction varies a lot but has not decreased that much on recent nodes. The resistance growth just outpaces the shrinking capacitance of the gates.

On top of that processors are faster, applications and sites are hugely more intensive to render, and the hardware (mainly antennas) suck up much more energy.

The ARM11 in the iphone 3 used <1 watt. The A13 in the iphone 11 uses 6 watts.