All economies behave in much the same way - like the game of Risk: sooner or later, there's only one player left, and they have it all. Without regulation to sustain good wages and jobs for the middle class, money migrates to the top - the wealth concentrated in the hands of the few and the rest of the society struggling to make ends meet.
The genius of FDR was to provide the "artificial" constraints that allowed the development of the Middle Class. Yes, WW2 was a huge boost, along with strong unions and Social Security, both of which are deeply hated by the wealthy who see unions and SS as an affront to their initiative and rights.
It's a sad, sad, day for America. We are witnessing the unravelling of our greatness, and the GOP is cheering it on for reasons that make no sense, not to even then - hence all of their strained rationales and bizarre grandstanding, while hiding behind "their love of the newborn," "their regard for motherhood and marriage," "their faith in American," and "their desire to restore our greatness."