I'll admit to some nerd shit and say that the Mars trilogy was an important part of my becoming a leftist. It got me to question my capitalist realism and think that maybe a better society is possible. I'm reading his most recent book though and he has this long, weird riddle thing where the answer was blockchain and I found it super off putting.
I don't know most of the people in the world, and trust is important in any transaction, so "cases where trust is important between two parties who don't know each other" covers a lot.