This is my issue with gpt-5. If you use the low or medium reasoning it’s garbage. If you use high, it’ll think for up to five minutes on something dead simple.

Can you be more specific about what type of code you're talking about, and what makes it garbage?

I'm happy with medium reasoning. My projects have been in Go, Typescript, React Dockerfiles stuff like that. The code almost always works, it's usually not "Clean code" though.