If I want to create a web app with a back-end, database, and some services, and I tell codex to do that with a specific stack and using specific paradigms to keep the code performant and maintainable, it's still a win over coding it by hand, as models can emit ~200char/sec compared with maybe ~10 for a really fast human. There's up front planning cost, and you will have to go back and massage some of the outputs a little bit if you're particular, but for sizeable tasks it still comes out to be a big win.

If you're just working on a single react component or an algorithm to do stuff with data, there's less chance to amortize the up front planning and verification so it comes out more of a wash.