That's not the issue being discussed. His engineering capabilities are irrelevant to him running the day-to-day operations of 5 of the biggest companies in the world at once.
They're not FAANG or JPMorgan, but he's not the CEO of Elon's Cheese Emporium on Main either. SpaceX has a market cap of $100B, Tesla $700B. That's bigger than any company I'm CEO of.
Actually, due to the downturn Netflix's market cap is only $125B, and Meta is $250B. So although they aren't all monstrously huge, I'd say Elon's companies are pretty big and require work to keep running.
Tesla is 65 on the Fortune 500, and Twitter was ~600 before the acquisition. SpaceX is also huge, but it's hard to say just how huge without it being public. The amount of commitment and work to become CEO at a company that's even 600 on the Fortune 1000 is insane. A quick google says there are 213 million companies in the world, I think having at least two in the top 1000 counts, no?