If the billionaire and high-multimillionaire class is liquidated, that’s a lot of resources and more importantly political power that is back in the hands of the proletariat.
What resources and where do they come from? Because ultimately, even if the final product or design is extracted from the US proletariat, the inputs (and increasingly the final product and design) are being extracted from elsewhere. With few exceptions (mainly agriculture, oil/gas lol, and some mining/forestry) everything we do, buy, or design at its base is extracted from elsewhere. Agriculture is its own can of worms since the labor is mostly imported and we need to end oil/gas extraction yesterday to have a habitable planet.
There are very few kinds of labor that don’t need some kind of material input to function. That material input comes from other labor that is mostly elsewhere. You can’t assemble a transmission without steel and someone needs to make the steel, which necessitates the extraction of iron ore. Even an economy of e-mail jobs still needs computers to function. Even if labor doesn’t need direct material inputs (like say a vocalists), the laborer still need food, clothing and shelter.