We certainly have enough compute at this point. 10^15 flops should be more than enough to run the brain by pretty much any analysis. Part of the issue is that evolution had at least 1 million such creatures over 52,000,000 weeks to improve since monkeys. So while human intelligent design of AI will certainly be a better algorithm than evolution, we may actually be a bit shy computationally of easily training an AI system, in spite of having more than enough to realize one.