Earlier quoted context omitted.
"You cannot test 320 million people, and do followup weekly testing on them." I mean, that is factually wrong. We could actually do that. It wouldn't even be that expensive. Of course, such a thing isn't really necessary. If everyone who wanted a test could get one without delay and get results back in hours, that would be sufficient to implement test and trace effectively.
I suggest you watch the videos from the Seattle hospital involved with the first corona patient. They emphasize that each test is expensive, involving PPE for the collector, the lab assistants, reagents and machine time. Then there's the question of accuracy and retesting to verify a positive result ...
The first corona patient is always going to be expensive. We had no testing infrastructure or really any best practices. We were unprepared in every way imaginable. Nowadays it doesn't have to be that way at all (and in fact it isn't that way). Watch videos of Korean drive through testing sites.