Amazon's current strategy is to have Stowers cram as many items in a bin as possible while maintaining a standard 'bin etiquette.' You have a specific number of items to cram in a bin each day, which you have to then balance with how much you care about the etiquette. They raised the number of separate ASINs (think types of upc) you are allowed to put in a bin and they're pumping new workers in at a faster pace than usual, cycling through the ones who give up
This leads to bad bin conditions. As ICQA, you have to count all the items in a bin, and you have a specific number of errors you're allowed to make before you're written up and a specific number of bins you have to count to 'make rate.' all the terrible bins cram packed full of items are then taken out, counted, and crammed back in. If it were possible to follow etiquette properly, they may not need to be emptied. If the item isn't there because a sloppy Stow or Pick smashed items in there so some would fall out, and they just left carelessly, you have to scan every item in the bin. Sometimes they're assigned to just scan every item in the bin anyway. 'cycle count,' as it were. The bad etiquette and poor stows/picks lower icqa's ability to make rate.
As Pick, you find one item crammed in the back and hidden weird, scan it, put it in a bucket on a cart, and move to the next bin.
The more stowers there are, the more stowers can break rules, because you have to be accused of having been the last one to stow/pick/icqa and only Stow gets in trouble for it. If you're a team of 200 Stowers, odds are someone else will jam one in before the day is over. Stow managers have something like 48 hrs to check a bad stow before it is no longer considered. Meanwhile, people who want to follow etiquette are forced to walk a quarter mile in some cases to find empty enough bins to follow etiquette. Sometimes you'll have a giant bottle of protein you need to stow and it's near impossible to find a place to put it, so you walk around for half an hour, ruining your rate.
And the managers haven't been bin auditing quite as much recently.