This is probably where I most fundamentally disagree with you, and the implicit assumptions here underpin much of your thinking in the piece. I think it is impossible for an individual to produce enough value that he or she is entitled to $11.5b of wealth. That present economic, political, and legal conditions permit this degree of wealth accumulation is irrelevant to whether it is justified.
For example, the privileging of private property rights over the rights of workers to democratically participate in the workplace is a historically contingent political and legal condition. There is nothing ‘natural’ about it. It only seems that way because that is our default ideology, or ‘lens’ through which we interpret and interface with the world. Before capitalism, feudalism was ‘natural’. And so on.
The crucial point is to realize these conditions are a function of political economy, not nature. Where do property rights come from? By whom are they enforced? (The State). Whose interests do they serve? What other competing rights might we privilege instead?
I don’t think you’re arguing in bad faith, but your frame of reference is certainly limited. This is particularly difficult to break out of because capitalism is so ubiquitous it’s nearly impossible to think about economics, morals, etc in different terms. But it’s worth trying.