Because what these models are trained on matters.
China is fucking smart. They have technical expertise to know that by feeding the model certain data, they can shape the outcome of questions posed.
Yeah, in the end, maybe both US and Chinese models can solve Fizz Buzz, or some Erdős problem.
And they can answer our inquisitive minds when we wonder, "Why is the sky blue?".
But deep questions about what is normal in the world they can change the outcome of.
And "Why is the sky blue?" is a deeper question than we think. Because it isn't blue everywhere in the world right now. And whether it is the fault of the US automotive industry, or aggressive investment by China in their own manufacturing base matters.
Of course, both have been responsible for pollution at different times. Growing up in Michigan near Dow Chemical I know this.
But depending on how they select training data answers can be nudged one way or another.
The US is smart too, and they have people working on the same things. It's ironically easier for me to talk about how China's security services are likely to shape their models' perception of the world. Which is a damn shame, because we deserve unbiased answers so we can all help our country improve.
Or countries improve if you want to take a global shared world view.