You're forgetting that it's a season for the pollens and so many people have allergies against that, many people start wearing masks at this season.
But the Corona has pretty much wiped masks off the shelves and those who need are having a hard time getting one.
And of course, much like the drug supply chains, I'm going to assume that masks are largely manufactured in (wait for it) China and factory lines are probably shut down.
Even if they weren't, the whole Just In Time(tm) inventory system will hammer you.
Nobody is going to staff up to make more masks because everyone knows that you will make lots of money for a couple months and then the demand will crash afterwards when Coronavirus has passed.
