I understand why you'd think this, but I believe this attitude is the result of a self-fulfilling prophecy from a system that rewards vicious competition. If the incentives were different, people could lift each other up just as easily as we tear each other down.
Watching children interact with each other shows that humans are more prone to sharing than stealing. Kids only start to care about competition when we praise the winners. It's capitalist messaging -- specifically neoliberal hegemony -- that presents life as a zero-sum game and forces people to adapt or die.
People have no choice but to conform to the culture we live in because that ideology is framed as the default "correct" worldview. As you say, it's framed in a way that participants can't refuse. So a culture of mutual exclusivity breeds selfish people, because selfishness is (mistakenly) seen as virtuous. Squid Games shows us what the future holds if we stay on this path.
To act otherwise, we need to be able to imagine otherwise
Overall the message in this article is a good one: we should put aside labels like capitalism and socialism and instead focus on the specific issues we care about