Once you learn how to understand and apply historical materialism and break out of capitalist canards like the myth of barter, it becomes much easier to come up with the things that make societies feel evolving, nuanced, and alive: internal struggles, subcultures and countercultures, political movements, economic bases, social mores and customs. That, plus having a variety of real-world examples to draw from to avoid falling into the trap of capitalist realism.
I used to listen to the Ricky Gervais Show and Karl Pilkington (same guy from An Idiot Abroad) would sometimes share his ideas for inventions but he never thought out how they would actually work, which of course made Ricky and Steve crack up.
In one episode he presented an idea for "a watch that counted down your life", i.e. if you were going to die in 3 days it would read "3 days" on the watch. When pressed to explain how it would actually work, he kept answering "just pop it on your wrist"
Anyway I think about that segment a lot when I talk to liberals about their conception of the political economy.
If he said how it worked, people could critique it.
I found a YouTube link in your comment. Here are links to the same video on alternative frontends that protect your privacy: