The current economy already has marginal income/wealth taxes to divide resources in a more “fair” way. Obviously they can and should be tweaked as changing parameters call for it to be tweaked in order to achieve whatever goals society is working for (such as a floor on standard of living).

This is true, but one problem is that in our current system fairness is always secondary. Something we tweak for when things go askew. A more ideal economy would flip this around, to ensure we don't allow some people to spoil it for others. And certainly not a minority spoiling it for the majority, as is the case all too often. The law simply can't keep up with the evil business schemes cooked up by a rich and greedy minority.