Why couldn't there be a law requiring all computers sold in the EU to have full documentation and complete controls for the user? I don't think this is impossib

Why couldn't there be a law requiring all computers sold in the EU to have full documentation and complete controls for the user? I don't think this is impossible or surreal. I think there are ways to check for certain things, if you have enough leverage. Also, if you demand high-level decription of hardware that is turned into circuits in europe, then that would make supervision way easier. As far as I remember there are also centers where Microsoft let's governments see Windows source code. Europe already has chips with the same problems, namely ARM. If there is political pressure to create a new one, I'm confident that they will enforce people-protecting regulations. Also, I don't think Chinese, Russian and USA cips have the same backdoors. Thus it us possible to protect against them by majority vote on output for given input.