I'm in China and have sold over 30,000 masks to the US (not for profit, but I don't have the cash to just donate them). We've sold to hundreds of different individuals at this point, and none of them are using the buying patterns you describe. The only people buying more than a hundred or so are buying for employees, hospitals, or doing a good job of lying about their intentions. Everyone is buying just a few and making them last.
So far I've personally taken one 10-pack of KN95s from our stock (of which I use 4 so far, on rotation. the other 6 are still in the pack), and about 5 surgical masks. There are strategies for extending the life if you do a little research.
The vast majority of regular people just aren't currently using PPE in the way you describe. After reading up on it, personally I think there's a useful middle ground between throwing away masks like you would in an ICU and completely doing without.
Sanitizer and gloves I know less about. But we do sell gloves and nobody is ordering more than a few boxes of those, either.
Depends on the situation. N95 masks can be decontaminated and reused pretty easily (IIRC 150C for 10 minutes). If you're only using them once or twice per week, letting the mask sit for 3-4 days is enough for most of the viral material to be destroyed by exposure to the normal environment.
I don't understand why people aren't talking about how disposable PPE defies this point at the low end. Hoarding a million masks doesn't make you better off than buying a thousand, but buying ten N95 masks is as good as buying zero. Masks, gloves, even hand sanitizer are consumables, so getting a little bit of them for everyone is as good as just throwing them into a hole and setting on fire. They work only when concentrated in bulk. Like a thousand of masks per household, or a million per hospital. Enough hand sanitizer that you can actually disinfect your hands every time you accidentally touch something outside. Etc.