You should see China. Big sheds crammed with rusting bikes were a commonplace sight, though that was 10 years ago now. You could tell the Americans by their helmets and going 2X faster on fully inflated tires.
Thing is, it doesn't matter. It is a bit of a rubbish problem, but there is no health hazard. If it gets people to ride bikes, that's far better than cars cramming every road everywhere.
They ride pretty slow, and don't lavishly maintain their bikes in general. You see people smoking while riding a bike in the city. This applies to the typical bike on the street. I understand there is a road bike culture in China now but that's a whole other thing.
I didn't get much chance to talk to people on the street in China since I only know a few words of Mandarin. Most of the software developers I was interacting with had better means of getting around. But I did walk past some working class housing, which is where you see these really large bike sheds. I suppose it's a hassle to carry oil and a tire pump down from one's apartment and back up.
Thing is, it doesn't matter. It is a bit of a rubbish problem, but there is no health hazard. If it gets people to ride bikes, that's far better than cars cramming every road everywhere.