Ok, I think I see what's bothering you. So basically think I'm saying it's not in people's self interest to cooperate. I'm not saying that at all. Cooperation obviously brings benefits to all participants. If no athletes were using roids, it would be beneficial to every single one of them, right? That's your real life prisoner's dilemma. So why are they all using?
Well, it's true that it's beneficial that they all stop using PEDs. But on the individual level, what makes sense the most is to keep using while everyone else stops. That way you reap the benefits of cooperation while achieving more than the others. And people try that. Cause it's in our nature.
I mean this isn't some controversial stuff I'm talking about. Marxists acknowledge this human trait and understand it is a problem to their political model, they just think you can change people.