That "theoretical" wealth clearly has a massive impact on the real world, so it's silly to pretend it does not exist. For example, Elon didn't buy Twitter with a giant bag of gold coins -- he borrowed against his wealth, which is mostly in stock.
Because no sane organization will lend out real cash over the same amount of collateral TSLA stock, and leveraged lending opens TSLA to extremely high risk as value dropping would means Musk will be forced to sell to cover/and or stake more TSLA. This is exactly how FTX failed - they counted their own token as their "asset". Spoiler: it didn't work.
Does this wealth have a high impact on the world? Of course it does. But does it has the same impact as same volume of cash? Absolutely not.