One weird but interesting theory : https://en.wikipedia.org/wiki/Strauss%E2%80%93Howe_generatio...

There are recurring cycles in the American/Western history, with each cycle lasting +- 20 years.

The cycles are High, Awakening, Unraveling and Crisis.

We're supposedly in the Crisis cycle, where there are major crises like war, depression,revolutions that would help the society to rebuild institutions.

This theory seems completely flawed as it applies itself retroactively, entrenched in confirmation bias, but still entertaining.