I'd say "citation needed" because OpenAI has A LOT of employees with Chinese last names. And they surely won't forget how stuff works the moment they change jobs. And surely a US employee non-compete won't be enforcable in Shenzhen.
"Why did Chinese citizens build ChatGPT in the US and let US companies pay for the computing power?" ;)
"Why did Chinese citizens build ChatGPT in the US and let US companies pay for the computing power?" ;)