right, and making any 'comparison' is subject to 'today's' costs, whether the electrical rate at home, or the gas prices at the pump. We often also 'assume' that we are going to do exactly the same things, and travel the same miles, in one versus the other, but with gas prices where they are, we might be more inclined to sit out for a while until they ever get back to 'normal'... we might feel more 'free' to burn electrons and go farther more often, versus the gas version which we keep sitting in the garage.
Financial comparisons are like this for everything. But, we humans sometimes change our habits based on current or future costs... which can then change the whole 'picture' that we were so interested in 'comparing'...