Is a giant sequoia tree, the largest of which was able to accumulate ~1350 tons over 2000 years, more successful than the quantity of worms that lived under it during that time? A continual measurement per unit time seems more fair to me than instant current weight at any given time. Maybe if it was possible to measure the biomass generated over the course of the year for each species. I'd think that's directly related to their energy consumption.

Because energy is a limited resource, ability to extract a higher share of it implies competitive success. Also, it's possible to convert and directly compare the energy potential lost to the environment through the various mechanisms for metabolism and activity.

Yeah, factoring in activities certainly gives us the advantage. I suspect most people have an idea of success more along the lines of mass of other species consumed. That seems unfair to plants though.

I feel some measure of chemical impact of the species to be the most level playing field, and that relative total energy consumption is close to the core of the question.