The basis for most leftists is not materialism but idealism rooted in the tradition of German imperialist philosophers like Heidegger and Nietzsche, who have been venerated and smoothed over and venerated again and then denied by the intellectual apparatus (the system of universities and journals that decides which ideas are received by anyone) until everyone has their own little micro tradition of Nietzschianism to suit their tastes. Nevermind their actual Nazi beliefs. It didn't bother Chomsky or Foucault or Zizek.

Of course, nobody engages directly with intellectuals. You don't even read, or even pay attention to the alt-media which whether branding itself as left or right has roots in the same intellectual tradition, you may occassionally still engage with the Jon Stewart style kids' entertainment/comedy adaptstion of the same ideas, but you guys get all of your news through the new pyramid scheme of Google and Amazon content creators.

So, it is no trouble for you to deny the entire intellectual tradition. You don't even know particularly where "your youtube guy everyone should check out" got his ideas, but at least he seems to talk like he knows what he is saying. And since he was likely bred on The Young Turks and other things like that, he is still many steps away from even investigating where he gets his ideas from.