The GPT models, in my experience, have been much better for backend than the Claude models. They're much slower, but produce logic that is more clear, and code that is more maintainable. A pattern I use is, setup a Github issue with Claude plan mode, then have Codex execute it. Then come back to Claude to run custom code review plugins. Then, of course review it with my own eyes before merging the PR.
My only gripe is I wish they'd publish Codex CLI updates to homebrew the same time as npm :)
This is solvable at the level of an individual developer. Write your own benchmark for code problems that you've solved. Verify tests pass and that it satisfies your metrics like tok/s and TTFT. Create a harness that works with API keys or local models (if you're going that route).