1. Did not use the UI framework currently being used in the web app; 2. Did not see the pattern, I always use header, but it skipped; 3. Wrong placement of elements, e.g. one element should have been on the left pane, instead it put it on the top right and so on.

I agree that on pure code they are OK, but I thought maybe I am missing something?

That is incorrect for most modern agents, which support multimodal inputs and are trained as such as it is an inherent requirement for things such as computer vision.

There's a reason OpenAI didn't release Codex-only variants of GPT 5.4 and up.