How can we know if people actually definitely died of covid if the test used to verify its existence is patently flawed?

How, after determining that a test is patently flawed and serving up no alternative, functional or otherwise, does one continue to use this test in order to verify the existence of the very thing that it was proven to not accurately locate?

Apply that reasoning to any other illness. "We know that this herpes test has been determined to deliver false positives consistently but it's the only test we have so unfortunately you have herpes. People need to be careful because everyone I tested today has it!"