I'm sure notebooks are used a lot for interactive exploration, but I would not use them for reproducible research, so long as they lack things like dependency tracking:
The bar in academia (over-generalizing here) was so low for so long that anything around including your code with your publication still gets placed under the historical title of "reproducibility" - that's probably where the confusion here is arising. I agree with your sentiment, but grandparent probably just meant "a lot of people release their code as notebooks".
It’s a step, but you’re both right. Things that containerize notebooks would count as reproducible, but they’re unwieldy and disgusting. I agree that while better than nothing they’re still not there.