It doesn't take 4 hours to code review a few lines of code for generating random QR codes.
The notion that only a human can effectively check code, will be viewed as a joke before this decade is out. Humans will be very inferior. Emphasis on very. Anybody that doesn't realize that yet, is still thinking in the terms of today, right now - and not understanding how fast this is all about to change, much less how much it'll change in a decade of time.
There will be button pushing monkeys, that are called ... code confirmation engineers, that sit at a computer and sign off on the AI systems doing code checks. They'll go to school for it, they'll almost never directly review code, most of them won't be able to even if they cared to (which they won't).