In my opinion you are just wrong.

It’s an absolute game changer, and it can now multiply your productivity fivefold if it’s a solo greenfield project.

Maybe half a year ago it was as you said. You had to wait for the agent to finish, you had to review carefully, and often the result was not that great. You did not save a lot of time.

Now I can spin up 3+ parallel conversations in Codex, each in a git worktree. My work is mainly QA testing the features, refining the behavior, and sometimes making architectural decisions.

The results are now undeniable. In the past I could not have developed a product of that scope in my free time.

That is what is possible today. I suspect many engineers have not yet tried things that became feasible over the last months. Like parallel agents, resolving merge conflicts, separating out functionality from a large branch into proper PRs.