Do they also suffer from high exponential growth in energy usage?
Your point that their usage doesn’t accelerate over time is valid, but as the link notes, this is still a significant energy burden on the country and should be addressed over time. It can be worked on in parallel to efforts to curb the growth of crypto coin energy waste, so there’s no harm in encouraging reductions to both.
They have figured it out. It's becoming exceedingly difficult to find incandescent Christmas lights these days. A quick check on two of my local big box store websites shows that non-LED Christmas lights are not even available for sale. LED lights use an order of magnitude less energy, so the current energy consumption is going to be quite different.