“It’s a somewhat depressing evolutionary outcome, but it makes intuitive sense.”
No, it doesn't. Explain how unicellular animals became multicellular without cooperation. Explain how humanity went from hunter-gatherer to landing a probe on a comet without cooperation. No doubt there are exploiters (we have all kinds of infections and parasites), but evolution has given us detectors (immune systems) to combat them.
If someone claims that selfishness is a virtue, demand that they provide actual evolutionary evidence from Mother Nature who has had billions of years of experimental history to investigate their claim. It's time that we collectively responded to Ayn Rand libertarians who would rather live in their imagined apocalyptic hellscape than reality. Demand that they face explain why Mother Nature permits only limited exploitation. Life is relentlessly harsh, sure, but nowhere do I see systems that have evolved in a zero-sum universe. It all seems ever-so-slightly positive-sum, which permits a variety of cooperative strategies to flourish.