How far down the rabbit hole would we be going to go with this? Who gets to decide what the capital cutoff point is for "too massive" and the contribution cutoff point is for "due to circumstance"?
If I don't believe in free will, and thereby claim you make too much money because you technically weren't responsible for any of your actions and never chose the outcome that happened, can I incite a communist revolution and seize your assets? If I feel someone won the lottery because they were lucky, do I get to take all their money because they didn't contribute value or "earn" it in a way that I find agreeable?
Can you give me an example of someone who is wealthy who earned their money in a manner that isn't arguably due to circumstance? As it stands, I can't think of an example that is materially different from a tech CEO who happened to be in the right place and right time. Go far enough back and every idea and execution on that idea is due to chance. But that applies to everyone, not just tech CEOs, or whoever the robber baron of the week is.