I suppose I should have some kind of solution-shaped conclusion to this thread, so here goes. My own contribution here is not that policy & governance solutions are actually stopgaps, and we need to do something else. To the extent that policy & governance — i.e. "politics" — can solve this, it's just regular old politics to do things like institute a wealth tax. We should do that, of course, but it is, as the kids these days say, a "big lift".
But not everything has to be policy.