Evolution works on the level of the reproducing organism, i.e. the individual.

Google group selection if you'd like to go down a deep rabbit whole but the upshot is, if pro-social behavior did not confer and individual advantage, the individuals who lose the trait would outcompete their conspecifics and the pro-social trait would not be fixed in the population.

In your Durkheimian analogy, sociopaths are cancer and while the body usually handles one off rogue cells, it often fails when tumors and eventually metastasis develop.

That can happen, sure, but the cancer's strategy is not a winning one - it dies along with the host.

Again, I'm not arguing for some naive Panglossian view. Things can get pretty bad transiently.

I just take exception at the cynical view that evil is somehow intrinsically more powerful than good.

"Survival of the fittest" is often misunderstood that way too, as survival of the strong and selfish, when, on the contrary, evolution is full of examples of cooperation being stable over long timescales.

Evil simply has more options available than good. Sure, those options, like all options, have pros and cons. Cancer, like sociopathy, can have a pretty good run even if it ends ultimately in demise.

I very much want to push back against any bias towards a just world. Bad people often live their whole lives without any consequence (think prostate cancer) while good people struggle (think my cuticles, which deserve much more than I usually give).

The cynical view suffers from availability bias - it's easy for us to think of someone who sticks out through bad behavior, but somehow gets away with it, precisely because it is not normal. (1)

But if you look at long timescales, it's pretty obvious that cooperation is the more powerful strategy.

We used to live in tribes of hunter gatherers, in constant danger from a hostile environment. Now, we're part of a global technological superorganism that provides for us.

If free-loading was a dominant strategy, this would never have developed.

(1) From the evolutionary biology point of view this can be explained by rate dependent selection- meaning the strategy is strong as long as only a small fraction of a population employ it. Durkheim would probably say you need these people to establish what the norms of a society are.