Eeeeeh, in a way, but many fetishes are also very much connected to emotion and rather basic instincs. From what I've heard from NTR fans, it's exactly the fact that they can emphatize with the suffering showed that makes it work. And taboo/extreme porn cannot function without the societal rules it breaks, so it's dubious to see it as a sign of societal decay – it doesn't really contest the norms, just leeches off of them.
Plus what you described is an extremely idealized vision of humanity's past. Both empathy and egoism are parts of our nature and while one might see today's world as radically individualistic and alienating, it's not like collectivism is without its own costs for people in the group. Empathy won't just die out, just like you can't really make everyone empathetic towards others. That's kind of why you need society/institutions so you don't have to rely on such individual tendencies, which are at least just as much temperamental as they are shaped by your environment.