I realize he can't just liquidate his wealth and buy food for everybody, and that leftist talking point is kind of dumb.
The problem is with how society regards "trillionaires" -- as if they must be generational super-geniuses who built the "best" product, instead of smart people who happened to build a product that benefited from *inefficient market competition*.
Billionaire-making products are generally ones where you benefit from using the same product that everyone else is using -- PayPal, Facebook, Instagram, etc. -- which means they are not subject to effective competition from upstarts. And that often results in a worse product (what Cory Doctorow calls "enshittification").
The "meritocracy myth" makes for bad policy, because it makes people less likely to support regulating companies like X or Facebook. He's a genius! Let him cook! But if you believe instead that these are somewhat shitty and in some cases actual harmful products that made people rich due to inefficiencies in the marketplace, then there's a stronger argument for regulating them.