I have been blessed with the opportunity to work with some fantastically bright people. A surprisingly large number of them become unstuck for the same reason: Hubris.
Overconfident in their own abilities, they engineer systems of dazzling cleverness; the very complexity of which turns them into snares that confound, befuddle, and ultimately humble their creators.
The true value of a person then becomes apparent. It is not intelligence, per se, but the humility to confront and acknowledge failure.
As Brian Kernighan once said: "Debugging a system is twice as hard as creating it in the first place. Therefore, if you create a system as cleverly as possible, you are, by definition, not smart enough to debug it."
Simplicity is of paramount importance in a world that grows ever more complex, day by day.
Sometimes, you need a self-aware simple-mindedness to achieve the simplest, and therefore best, result.