I think we are already way past single-human intellence. No one person understands (or could possibly understand) the whole system from the silicon up. Even if you had one AI "person" a 100x smarter than their coworkers, who can solve hard problems at many levels of the stack, what could they come up with that generations of tens of thousands of humans working together haven't? Something surely, but it could wind up being marginal. Exponentially smarter AI meets exponentially more difficult wins.