Explain open source, free software, linux community, lemmy / the fediverse, and many many other things not formed around profit, largely maintained by people in their free time motivated by community over profit.
People aren’t inherently greedy. People are born into a system that rewards greed, and punishes altruism. There have been many different societies with many different political and economic systems, and capitalism is a fairly new one all things considered.
Rational self interest is irrational. If only a few can succeed, chances are you fail. If everyone only looks out for themselves, then everyone fails. Humanity’s biggest strength — what set us apart from many other animals — is our ability to work together and look out for each other.
Capitalism doesn’t work, and is destroying the Earth.