I have never heard of a case where someone lost bitcoin because of backdoored RNG, but just as we can't verify it's generating true randomness, we can't complain they're stealing bitcoin either. I mean, think about it. You wake up the next morning, and your wallet is emptied. What do you do? You tell a journalist that AMD and Intel insert backdoors? With what evidence?
I understand what you are saying. But considering how big of a market share AMD and Intel chips have, and if it was a widespread backdooring problem, I think we would have too many complaints not to understand that something is seriously wrong. Especially if governments have a way to meddle and apply blows to Bitcoin that they hate. It would be a great way for them to attack Bitcoin and then spread FUD how unsafe and a big scam it is. They wouldn't be able to restrain themselves.