what is the evolutionary advantage of enjoying anal sex?
what is the evolutionary advantage of using contraception?
what is the evolutionary advantage of enjoying artificial sweetners?
what is the evolutionary advantage of enjoying music?
humans are quite good at finding ways of hacking life to give them reward for non-evolutionarily advantageous behaviours.
We didn't evolve with drugs, our suseptibility to addiction to drugs is because addiction to natural reward triggers: food, sex, love, all gave huge evolutionary benifits.
People say addiction is a disease, but what they don't realise is it's entirely natural.