The need to steelman Yarvin came to my while I was running a few days ago.
The best I can come up with is a modification of Kling’s civilization/barbarism axis, to wit, his contribution can be described as:
Assume the world slides back and forth on a spectrum of civilization and barbarism. Each increase in civilization comes with a decrease in barbarism, and vice versa (both have benefits, structure, dynamism, equilibrium, etc). Yarvin can be thought of as contributing the thought that civilization can decay in place. The benefits of civilization can decrease with no increase in barbarism. Basically a decrease in structure without an increase in dynamism.
Now that I’ve written that out (in less than 45,000 words) I will go back to disliking Yarvin.