I don't think that's quite true, the Saudis arresting people in 2017 or 2018 whenever it was, they demanded they make payment to the state from their private wealth, they weren't able to just seize it. It's more akin to russia, that while billionaires have private wealth, they don't have any power compared to the state and their wealth (or their life) can be demanded by the head of state, so while the lines are certainly blurry, I wouldn't say there's no private wealth in these countries at all, its not totally independent from the state, and the only people who can acrue it have links to the state, but it does become private wealth at a point