Other person here.

I'd say destructiveness of humans is kind of a Bell curve shape where the X axis is wealth. Cavemen don't affect the environment that much mostly because there can't be that many of them. Their production methods can't sustain large or dense populations. Then people in 1900 are quite destructive because they can sustain billions of people while spewing pollutants, etc. Then people today are less destructive because we have the wealth to care about such things. Wealthy countries are doing pretty well.