IQ is only one possible (not necessarily required) attribute of competence.
I've always maintained that IQ needs to have a friend...the WQ, the Wisdom Quotient, which would be a measure of both emotional and intellectual maturity. It must by needs be bound to a measure of intellectual curiosity and a measure of critical thinking ability.
To put it in rather mechanical terms, if you measure an engine's horsepower to prep for a drag race, you must also test both track conditions, your car's ability to maintain traction and the skill of the driver.
If IQ is a measure of your mind's "horsepower", this "WQ" would be a measure of your "traction", the ability to translate all that power to getting the vehicle down the track, and the emotional and intellectual maturity would translate to the skill of the driver.
An eleven thousand horsepower top fuel dragster isn't going anywhere without large enough slicks in the rear and indeed, without adequate driver skill behind that tiny steering wheel, even if it did get traction, it may wind up rocketing straight into the wall and bursting into flames.
It's one thing to have a massive brain with a lot of mental horsepower, quite another to have the ability to harness that power and translate it into useful work.
Having just finished an arbitration hearing where I was grilled for hours by a dishonest lawyer, who I suspect had a middling IQ, and who was fond of asking speculative compound questions while insisting that my answers be yes or no, I am very sensitized to the need parse out concepts that contain a mixture of facts and unexamined, sometimes biased, assumptions.
I've encountered a few attorneys like that, but surprisingly I've also encountered more than a few debaters who try that tactic.
I'm sure I am not alone in this.