I use “Marxism” and “right-libertarian” loosely to refer to ideas that, respectively, focus on the dichotomous struggle between the bourgeoisie (owners of the means of production, especially people who extract labour from their employees or consumers) and the proletariat (people who have nothing but their work to give), or the dichotomous struggle between the winners (those who benefit from capitalist conditions) and losers (those who have not managed to pull themselves up by their bootstraps).
Both these ideologies present a zero-sum view of humanity, though they take different perspectives: Marxists focus on the conflict between collectives, and right-libertarians seem these conflicts as individual. Both have a zero-sum character that reminds me of Social Darwinism. For one to survive, the other must be eliminated. This kind of winner-takes-all thinking is pervasive and seems to have brought us nowhere.
The frustrating thing is that right-libertarians often have valuable things to say about freedom of speech and expression, though they are often dismissive of how groups of people experience systemic oppression. A lot of them think that sexism, racism, homophobia and transphobia will be vanquished in the free marketplace of ideas—or that these forms of prejudice are even justifiable because they continue to exist. And Marxists have an acute understanding of how economic inequality and exploitation lead to poverty, suffering and misery—but they don’t always care about individual rights and support the suppression of dissent. And like their right-libertarian counterparts, they may pooh-pooh racism and other systemic oppressions—or uphold them—because they’re secondary to the class struggle. (And then you have the identity-reductionist counterparts, but they are distinct enough from Marxists and right-libertarians that I’ll deal with them separately.) All these are counterproductive, reductive mindsets that ignore the complexities inherent to human existence.