it has happened, especially in underserved cities , but the problem we have here is that it is a virus we know virtually nothing about and its harming/killing people at a fast rate. A flu puts people in the hospital, we typically know what to do, and we utilize specific resources. But filled hospital beds are different than filled hospital beds during a novel pandemic. This thing puts people in the hospital and you have a best guess scenario for how a treatment MAY work on a single individual. Thats why people like your friend are being used so much, they need all man power they can get because this virus is nasty and right now needs to be approached at all angles.
(I know I'm going to have to answer this so YES, the flu is nasty, but the flu is not new and we know a lot about it,. )