This is a very well known problem for many kinds of screenings, and the solution is not as simple as you claim. You can't just repeat the test, that is general

This is a very well known problem for many kinds of screenings, and the solution is not as simple as you claim. You can't just repeat the test, that is generally not where the problem lies. You'll get a second positive result and still don't know if it's a false positive or not. And in many cases there aren't other non-invasive test you can perform. If you can't actually determine reliably if some anomaly will cause trouble before removing it, whole population screening will cause unnecessary operations.