The medical establishment is incredibly hidebound and amazingly resistant to common sense. That's why all real medical progress historically has come in times of war when out of desperation some doctors are brave enough to toss the book and go back to practicing actual medicine, focusing on the needs of the patient. Figure out what works first, then when you have the luxury of time let the researchers provide an explanation and move it into orthodoxy.
It's been obvious for some time that front-line doctors are ignoring the received wisdom from the medical establishment and HCQ+Zinc+Azythromycin has become the de facto go-to treatment for most patients.