What changed
This is essentially "Data Flywheel" argument. I do agree that closed-model deployment leak data pipelines, but that takes time. Zai likely benefited from this, but it benefits far more from direct user usage of its data plan like when I make choices on ZCode.
As more global devs use GLM, it directly builds up Zai's data pipeline. Unclear to me how much this gets shared on China's data ecosystem, but since GLM is open, you can theoretically rebuild a whole chunk of that over time (especially if — via @tphuang