I bought a case of N95 masks about 15 years ago. IIRC it was 10 boxes of 10. We've used many of those over the years as dust masks but still had about 40 left a month ago. I dropped some off at my brother and nephew about 3 weeks ago and they thought I was crazy. Told then to stock up on food and TP too.
Anyway we have 33 now plus what we keep in our emergency kits in our cars. I've offered 20 of them to one of my nephews that works in an ER. I'm hoping that he won't need them as St. Louis still only has a handful of cases and is on lockdown.
There are ways to reuse these masks and folks are working on a way to scale the procedure. Many of these can't be washed or bleached as they are made of what is essentially paper. But UV light will kill viruses. It would seem to me that there are all sorts of manufacturing plants out there that could crank these out in one fashion or another. My guess is that they would all need to be certified by the FDA before distribution. That is probably the biggest hold up.
I understand why we might not have 10s of millions of these in warehouses, but its a bit maddening that we can be pumping these out by now.