Yes, a better rubber duck is a decent description

The LLM will often miss the most obvious simplifications. And if I ask it to present me with six approaches how we could solve a problem, chances are we will settle on number seven or eight, both my ideas after rejecting all the other six. But those first six were still valuable for coming up with the version we actually settle on. Making the rubber-duck talk is genuinely useful.

And the rubber duck is actually pretty good at the localized grunt work, so you can spend more time talking with it about big-picture stuff