Not defending people who steal, but Amazon especially have purposefully chosen to use a system whereby they don't really track this sort of thing: because it's historically been cheaper for them to just accept returns without checking than to check them.

Previously the small losses from people who were stealing were < the price they'd have to pay to have systems in place to check this stuff in depth.

I've received stuff from Amazon where they've sent me an empty box with no product in it - because the previous person probably "returned" it, then I have to be the one who reports "uhh...the thing I bought isn't actually in the box".