It's the fact that they were idealized that makes this dip into their intimacy so strange.
But basically, those communications look a lot like ones that I would have with my own friends. And when I was a students, we were careful about spending 10 euros. Now, we have casual chats about buying a sauna for the garden, and if you think about it, it would sound crazy to someone making minimum wage.
If I had billions, I would talk as casually about huge amounts for actions with big consequences, because I'm still ...me. And I would still make jokes like "you have my sword" since we quote LOTR for fun, not because of social status. What? You thougth billionaires were taking all their texts seriously?
Also, calling people out for making mistake that cost you is kinda what everybody sane does. And apologizing to people when you made a mistake is not being submissive, it's being decent. Again, it reads like text I would send myself.
All in all, it seems pretty standard human behavior to me.
Now you may feel shocked that regular humans have so much power, but remember:
- a lot of luck is involved
- some skills like managing stress or being persistent may matter more than a lot others and those people may have much more than the average person
- this is by design in our system, the problem therefore is not that humans are humans, but that our system promote profiles that you don't think deserve it
- nevertheless, managing tesla or spacex is not something most people would succeed at, so there is probably some human traits those texts are not showing that make them capable of doing billions of dollars of operations