Though I mostly agree with you, sometimes I feel human nature is just ugly.
This is not true. Humans are created by the material conditions they find themselves in. “Human nature” when in an abundant environment is very different, we can see this among remaining hunter gatherer tribes like the Hadza (watch/read the whole thread).
Living in capitalism is what makes people the way you see them. Competition for resources with your fellow workers and an endless toil for the benefit of someone else enforced by the threat of homelessness and death if you don’t take part.
Being an asshole under capitalism is as natural as coughing is in a smoke filled burning building. If you don’t know anything different you can’t see that to constantly cough is not the natural way of human beings. When you take people and put them in different material conditions you get a completely different outcome.