You seem to believe that humans, on their own, are not stochastic and unpredictable. I contend that if this is your belief then you couldn't be more wrong.

Humans are EXTREMELY unpredictable. Humans only become slightly more predictable and producers of slightly more quality outputs with insane levels of bureaucracy and layers upon layers upon layers of humans to smooth it out.

To boot, the production of this mediocre code is very very very slow compared to LLMs. LLMs also have no feelings, egos, and are literally tunable and directible to produce better outcomes without hurting people in the process (again, something that is very difficult to avoid without the inclusion of, yep, more humans more layers, more protocol etc.)

Even with all of this mass of human grist, in my opinion, the output of purely human intellects is, on average, very bad. Very bad in terms of quality of output and very bad in terms of outcomes for the humans involved in this machine.