All three are of your examples are wildly different in that they’re top-tier individual contributors. Of course you can become a prolific writer without exploiting anyone. A more fair comparison would be something like politician.
I think billionaires are much closer to what I mentioned than to politicians. You can tell this by the fact that most billionaires have engineering degrees or were tinkerers.
One defining quality is that billionaires need to scale work that often involves management. In this case consider prolific basketball coaches, or generals in war.
The reason I shy away from including politicians, is because their m.o is starkly different: it’s all about status.
Sure, coaches and generals are also much better comparison.
Either way, I think your argument is weak. “Sure you feel this away about billionaires. But change ‘billionaire’ to something different and your feelings change.”
Well, duh. That’s not even an analogy. You’re just literally changing the subject of the sentence. Billionaires are super different than writers in ways that are relevant to this discussion.
Then, you can be more confident in your conclusions. You may still be off, but heck, you would have subjected yourself to much more critical thinking than average, and can be much more confident in your opinions.