I do love cats, but it's not clear to me what an extremely high IQ cat would be useful for. I suspect it would fall somewhere between lethal and unusually annoying.
A smarter cat plots better ways to murder small animals and calculate more comfortable resting places.
Having a smart ones he seemed to be doing all the cat things pretty optimally.
For social conflicts him being huge enough that other cats and roaming dogs where scared was a lot more useful.
A super high IQ could maybe useful for hunting in dangerous places (it would avoid getting hit by cars and other hazards in cities).
