I agree with you on the use of the past timeline. It goes very slow and still feels like a disconnected show. Is like a show inside a show, but that right now is too new to build a relationship. Besides the black goo that might have been the caused of the leaving the world in shambles, there is really not much to go on with.
I saw a youtube video theorizing that the senator is the voice of the AI, and that it might have been an agent built on his personality as he uses the therapy used on his sister to control the population. But besides that being a very early draft theory, I don't even see what is that relevant with the main arc post the revolt of the Silo. This season feels like a soft reset of the story and trying to rebuild a new show with the same characters but with different objectives than we saw on the previous season.