Earlier quoted context omitted.
Are there really no longer any open and relevant research issues around this topic? Is humanity's understanding of CPUs, how they work, how they should work, is it all wrapped up and complete? Not really my field, so I truly don't know. But I'd be a little suspicious of someone who claims there's nothing new to learn here.
I don't think he means innovation which seems to be what you are implying. If you take a current working computer system, there are no "mysteries" in the existing hardware where the hardware designer just threw up their hands and decided to hope it would work. Sure when you throw in environmental factors there is certainly unpredictability in terms of hardware failure, but actually understanding what the system is do…
The other thing is that while the brain is highly complex, that doesn't mean that people who work in it have managed to master something more complex than CPUs (or house wiring, for that matter). They may simply not really understand what they're doing to the same extent.
To me, the thesis in the original post is this "[if] there are people who are brain surgeons, it cannot be so much harder than being a really competent programmer."
I tend to agree, because I think that some types of programming push people's mental ability and sheer stubbornness past the point of human ability. In short, it will take all you have, and there will still be things you just can't understand or do.
If you define the task as "the things that we understand and can do", then by definition is is not equal in complexity to the brain, but like I said, I think the statement is a contrivance.