I think the point of mentioning Codex was that the author of the post has no relationship with Anthropic, even as a user.

It's said to imply they have no bias. But someone using Codex or AI agents heavily already have a bias here, just to be clear. Because the discussion isn't just about bun/anthropic/zig/rust, but also between AIs role in coding. So them touting their use of Codex, while not Claude, can still be a bias, especially in the direction they're trying to absolve themselves from.