by that reasoning someone with one hair on their head is not bald...a ‘positive’, from a medical perspective, means essentially nothing, unless your goal is to create a panic.
Well, from a medical perspective, if a patient has fever, low blood oxygen, and ground glass opacities on a chest CT AND the COVID PCR is positive, it means quite a bit. It also is quite helpful, with the identical clinical scenario, if it is negative.
Use of the test for population screening was probably unwise from the start - but there have been so, so many unwise decisions, right from the start, that that one isn't in my personal top ten.