Communism was/still is (depends on how you feel about China) a system that billions of people lived through. I think there’s been a great amnesia about this in younger people who’ve never met someone who interacted with Really Existing Socialism
It's no accident that American colleges don't have courses dedicated to teaching students what life was like in the Soviet Union. They had money, and they had people living in nice places with cars and people who lived in ghettos and were a decade+ away from automobile ownership if ever. A reality check isn't what you need if you're raising a generation of utopian idealists.
I was born in the USSR and grew up through the restructuring following its fall. We weren't well off, and my whole family(including extended) basically lived in a 2br apartment. I don't remember feeling poor or anything, that was just the life we knew, and I don't really remember seeing people who were 'better off', but I wasn't looking for it at that age. I have recently started asking my mom about what she experienced during her work years, but that process is just starting for me.
Anywho, my reference to communism not taking off is mostly to the utopian idealogy, I understand many people live/d under communism, but it was really just socialism with some caveats.