From the NC article:

One thing we miss in this process is that if ownership of wealth was equally distributed, it wouldn't matter whether r > g in terms of its impact in inequality. Or more precisely, institutional settings can be designed to combat any social force that concentrates wealth if we so desire, and if it is politically palatable.

I do not see a relation between these two statements. So we just need the institutions to concentrate on giving "r" to everyone? Firstly, that would be the ultimate acknowledgement that productive "g" is for fools, that "g" has to be exploited with meager reward. Someone has to produce more than "save" anyway. Secondly - Capitalism is then the ultimate casino, and we are forcefully invited to play.

Institutions could be designed and build to do any good - until they co-opted to do the opposite. The post-WWII institutions are failing for exactly this corruption reason.