Scholastic theology comes right to mind.
Scholastic theology was complex, but so are many theories more highly regarded than it nowadays. Like physics.
Or consider the modern economy - when I contemplate a wireless mouse, it seems vastly more complex than the problem it solves (a mouse which requires a wire), yet, the wireless mouse still works & is nice to have.
In fact, you could probably consider every single technology and economic system a counterexample to this Taleb quote - it's all epicycles upon epicycles, techniques to solve problems which you only have because of earlier techniques y...
Another month has passed and here is a new rationality quotes thread. The usual rules are:
And one new rule: