Okay, once more for the cheap seats.
the first paragraph you excerpted; "
... Although there is a common misimpression that the viral load tests actually count the number of viruses in the blood, these tests cannot detect free, infectious viruses at all;"
This means that the PCR test could not diagnose if you were infected with HIV=AiDS and can not diagnose if you are infected with Covid-19.
As for your second excerpt, this is essentially a more elaborate, somewhat quicker innovation on the original process, but as you finally state, concludes a SUSPICION, NOT a bonafide conclusive diagnosis. From my link, here's what you conveniently leave out,
"....
The authors say this test is the basis of all current COVID-19 testing. They say, correctly, that a positive/negative result is insufficient. Labs must provide the Ct value; without it, RT-PCR is unsuitable as a specific diagnostic tool."
..... Nonetheless, people should recognize that even a properly-conducted PCR test is not determinative: it only gives a rough probability that a virus may be present. From a biochemical perspective, RT-PCR barely even qualifies as a quantitative assay, but as a screening tool it is better than many of the proposed alternatives."
Any medical procedure based ONLY on a suspicion is dangerous. Period. this is why you have all those false positives and negatives. The "better than nothing" attitude is of little comfort to a patient being treated on the basis of a faulty test.
Capice?