Am I missing something? I don't see the problem here.

Did we need a study to figure this out? Well, yes, we probably did. Easy access to PPE does not guarantee its use in many settings, after all (as evidence, I refer you to all the morons wandering around with their noses poking out of their masks. Add to your "breaking news", for those who didn't know: the nose and mouth are BOTH connected to the lungs.)

It makes sense for employers to want to know whether PPE will actually be used, before spending the cash to provide it. And the CDC certainly has an interest in determining that it will, the better to encourage employers to pony up.