This is actually part of the PROBLEM - with so many bridges on the "worst possible category" it becomes a bridge who cried wolf scenario. There is no way to highlight "yeah this one is going to fall down tomorrow" if the worst you can do is mark it "this bridge bad like 42k others".
You need some form of a "stop ship" where inspectors get some number of "no way, close this entirely" that they can use without repercussions or something.
They sort of do have that power. They have the ability to lower the max vehicle weight and eventually it gets lowered to where no real traffic can go over it. Grady talked about it in the video.
I have a feeling the politicians already know partial cybersecurity isn't an option, and don't care. Certainly, the intelligence community advising them absolutely does know. We don't even have to be conspiratorial about it: their jobs are easier in the world where secrets are illegal than in the world where hackers actually get stopped.
Not with physical security either, I'm afraid.