It seems equally as likely that it is an issue of over-expecting what a worker can reasonably perform. Why is under performance the more likely scenario in your mind?
>it isn't clear to me that this is either widespread
If this were the only occurrence of "Amazon Contractor" and some combination of "pee", "bottle", "no time for bathroom breaks", etc. I would be more inclined to take the route of "a few bad workers". However, these stories have consistently made news since at least 2018.
Additional factors, which not conclusive themselves, that lead me to doubt the Amazon narrative include such things like 74% of respondents to a survey conducted by Organise reporting that they avoid using the washroom for fear of missing targets[1] - indicating that perhaps at least some fault lies with Amazon for setting unrealistic and unnecessarily burdensome targets.
[1]https://static1.squarespace.com/static/5a3af3e22aeba594ad56d...