Looking at birds and dinosaurs.
It seems to me they were evolving pretty much every aspect of "intelligence". A dinosaurian mutant with a thumb could well have "taken off", and in a few million years evolved into a sophisticated tool-maker.
Homo Etcetera has been around how long? Not very. And has evolved.
I think "intelligence" is every bit as much an advantage for filling an ecological niche as teeth and claws and is an inevitable outcome of life allowed stable multicellular growth.
Unless that life is wiped out down to the cellular level every once in a while.
Arf