For one, you will never force all vendors to comply, as some are completely outside of the jurisdiction, like China. Secondly, even if you did force vendors to comply, you've just given any new startup a massive leg-up on R&D, which the existing vendors discounted for them.
I don't think it's realistic, and there are already methods by which the code has to be reviewed externally, at least in principle. I want to improve the existing processes, not move to a new model.