Claude doesn’t suck. Your harness probably does.
I say this as someone who currently prefers Codex.
Most “this model is garbage” posts aren’t controlled comparisons of models. They’re reports about an entire system: context quality, instructions, memory, tool access, task decomposition, permissions, testing, recovery, and verification.
If those layers are weak, replacing Claude with Codex, Gemini, Kimi, or another model just changes which model fails inside the same unreliable workflow.
The model still matters. Different models have real strengths, weaknesses, and regressions. But model capability sets the ceiling. Your harness determines how consistently you reach it.
Before blaming the model, ask:
Did it receive authoritative context or a pile of stale text?
Was the task scoped with an observable completion condition?
Could it inspect the relevant evidence?
Did anything verify the result?
Did an intermediate action get mistaken for completion?
Can the system recover when something fails?
I built a local Codex system called Lumen around these problems. The biggest improvement didn’t come from finding a magical prompt. It came from treating the AI as one component inside a governed, stateful, verifiable system.
Sometimes the model really does suck at the task. But most people haven’t isolated that variable well enough to know.