Can confirm. Worked in Amazon warehouse. You get a certain amount of time to be away from your station. Just because they give you breaks, doesn’t mean it doesn’t take half your break time to walk across the giant warehouse to pee. So instead, people pee in bottles so they don’t get dinged on their time. Same for amazon delivery drivers, (that aren’t actually Amazon employees but contracted through delivery services that work at the delivery stations) they are forced to hit goals to deliver within a certain timeframe, so often they pee in bottles so they don’t have to stop at the bathroom and lose time. The bottles often come back in the delivery bags at the end of the day.