Computers work by performing a sequence of computations, one at a time: parallelization can cut down the time for repetitive tasks such as linear algebra, but hits diminishing returns very quickly. This is vey different than the way the brain works. the brain is highly parallel. Is there any reason to think that our current techniques for making algorithms are powerful enough to produce "intelligence" whatever that means.
All biological organisms, considered as signalling or information processing networks, are massively parallel: huge amounts of similar cells with slightly different state signalling one another. It's not surprising that the biological evolved brain works the same way. A turing machine-like sequential computer powerful/fast enough for general intelligence would be far less likely to evolve.
So the fact that human intelligence is slow and parallel isn't evidence for thinking you can't implement intelligence as a fast serial algorithm. It's only evidence that ...
Haven't had one of these for awhile. This thread is for questions or comments that you've felt silly about not knowing/understanding. Let's try to exchange info that seems obvious, knowing that due to the illusion of transparency it really isn't so obvious!