Not going to downvote, but I do think you’re lacking quite a bit of insight into the reasons human society exists at all. Cooperation is the reason human society exists at all, so saying we’re inheritly selfish is kinda laughable in that context.
I would encourage you to look up information on dialectical Materialism and the necessity of capitalism as a stage in that dialectical.
Capitalism had a purpose, and it’s past time for us to move on.