It makes them effectively have similar societal power as the middle class. They don’t have anywhere near enough money to wield institutional power and at most exert control on the lives of a handful of employees or tenants or whoever. They can’t get their names on institutional buildings.

They could retire immediately and live on that net worth but their standard of living would be greatly impacted by doing so rather than continuing their income-generating activities.

They could face major financial consequences by spending their money frivolously or losing it in a lawsuit. They have a low enough amount of money that they could gamble it away or lose it all in a bad business investment.

I think that makes them much closer to the middle class than the truly wealthy who cannot lose their fortune even if they tried their hardest and have essentially no feasible way to have their standard of living lowered. For example, if Twitter shut down after Elon bought it, there would be no detectable difference to his lifestyle or buying power. There is no amount he could gamble at a casino where he would lose his fortune.