High false positive rate (I’m talking like more than 1%) means
(1) you are overwhelmingly unlikely to actually have the disease even if your test comes back positive but you don’t have obvious symptoms
(2) the pool of people testing positive is completely dominated by false positives. The fraction of people testing positive that will actually have the disease would be very small, so you lose the epidemiological benefit of the test (now you can’t actually track the disease well).
So — test is useless for people like you and me who don’t have symptoms or a strong prior probability of having covid BEFORE the test, because even a positive result is overwhelmingly more likely to be wrong, AND now the epidemiologists trying to actually track the disease are instead overwhelmed with false positives so the true signal disappears. It’s bad all around. You could imagine using this as a screening tool, but the false positive rate has to be small enough for that purpose as well (like, less than one percent).
I'm assuming there's high false positive rate. If the test has even moderate false negative, then yes it's worse than useless.