Considering the dropped cases apparently they didn’t all lie. But to answer your question, bringing in funding is both one of the most important and difficult

Considering the dropped cases apparently they didn’t all lie. But to answer your question, bringing in funding is both one of the most important and difficult jobs for a professor or researcher. So I assume some lied to unethically get a career boost, thinking they could just casually omit disclosing a role in China to get a chance at more funding. The vast majority of scientists just want to do their job (research), but they have to play the funding game which gets deeply entangled with political bullshit. China offers the carrot (thousand talents) while USA offers the stick (China Initiative)