Is there another human that could get me even better performance given the same parameters. Probably yes. In the same amount of time? Maybe, but unlikely. In any case, we don't have anybody on our team that can think of 20 different ways to improve a large and complex SQL script and try them all in a short amount of time.
These tools do require two things before you can expect good results:
1. An open mind. 2. Experience. Lots of it.
BTW, I never trust the code an AI agent spits out. I get other AI agents, different LLMs, to review all work, create deterministic tests that must be run and must pass before the PR is ever generated. I used to do a lot of this manually. But now I create Claude skills that automate a lot of this away.
There are plenty of examples from talented individuals, like Antirez or Simonw, and an ocean of examples from random individuals online.
I can say to you that some tasks that would take me a day to complete are done in 2h of agentic coding and 1h of code review, with the additional feature that during the 2h of agenti coding I can do something else. Is this the kind of evidence you are looking for?