Ray Dalio talks about this phenomenon in his free book Big Debt Crises. He shows data that debt bubbles are cyclical and exhibit the same characteristics each time. The debt bubble that played out from 1927-1940 also exhibited increasing wealth inequality which led to massive social and political volatility. In relation to that cycle we are around 1936.

Income inequality and political crisis will likely be very high in the coming years (even as it's already high as you can probably tell by recent events) and we might see some pretty stark changes in our economy and policies. Perhaps more social programs to lessen the damage of the gap such as free healthcare or universal basic income. The recurring bubbles do hurt but eventually they give way to the next cycle of debt inflation and exuberance.