The cost of the Twitter acquisition to much will have been much more than $40B. Since he had to liquidate stock to make the purchase happen, you don’t get face value for the sells and the lowered stock price is then reflected in the rest of his net worth.
I’d be surprised if the hit to his net worth from the purchase as less than $80B
80 billion USD is still a ridiculous amount wealth, which puts him in the top 20 richest persons in the world. For all intents and purposes there is no difference in 80 billion USD and 800 billion USD. You are still more rich and more powerful than many nation states. The fact that you can blunder this horrendously, and loose this much money, and still keep all your wealth and power is proof of you parent’s point.
It's all just numbers at that point though, the actual money means nothing.
He gets to be in the public eye and news all the time. Gets to be defended by fanboys while making fun of disabled people and laughing at design people who work with Figma. He gets to delist anyone he dislikes. This role gives him power and attention on a global scale.
Seems like a great investment of $80B if that floats his boat, which it seems to.
There is potentially more to it than that since he also had to leverage his stock for part of the purchase price. There will be interest on that, and since the stock price has been rather volatile, there may be margin calls as well.
I’d be surprised if the hit to his net worth from the purchase as less than $80B