This video is about HIV, which is very different from coronavirus. Indeed, PCR is kinda useless when testing for HIV. It is a serious disease that warrants the highest levels of test precision possible. People need to be 100% certain they have it, and in what quantities before committing to medication and behavioral changes for their entire lives. It is also much harder to transmit, which removes the need for mass testing. However flawed the PCR might be, it is a very useful tool for easily transmissible diseases such as covid. We would lose the ball if we depended on blood tests solely.