First of all, thank you for such a well-informed analysis.

My studies have taught me that the most critical ingredient for civilization is justice. According to 'real justice' there are three conditions of justice for the economy: freedom, the presence of a "democratically distributed income," and the absence of exploitation (i.e. 'wage slavery': people paying others to be used as machines for the monetary aggrandizement of their employers).

The more of those conditions that are met, the more just the economy is. Only the first of them is currently met in any nation.

Those conditions are indifferent to the presence or absence of ‘capitalism’. Meeting the second or even all three does not require any limit on income/wealth. Meeting the second would increase sustainability; meeting all three would all but assure it.

"For Crying Out Loud, Accept That A Solution Actually Exists" (a "3 min read" — including options for further reading — here in Medium)