"Smarter" is too vague. A group can compensate for individual weaknesses or even converge on a hard-to-make prediction given sufficiently uncorrelated outputs; basically the idea behind ensemble models / wisdom of the crowds. But a group of 1000 dumb apes would never achieve categorically-above-ape intelligence, probably not even "genius" ape intelligence. Groups of unintelligent agents come with downsides as well, like the ant death spiral.
Do they not become smart*er* though?