Often at Amazon you have the "Frugality" principal taking the wheel for short term savings, even with long term massive costs. They're notoriously cheap, think like no free coffee cheap.
One of Jeff's guiding principals that he infused the company with, is that workers are lazy and will take advantage of any moment to not be productive if you let them. If you're nice to your workforce they'll take advantage of your kindness to do nothing. This happens on the corporate side too with all the PIP stuff.
In the long term I don't think this is going to work at all, either they need to change their policy and attitude or literally no-one will work there given the choice lol. (This is more on the SWE/Corporate side and less on the warehouse side, often Amazon is the only/best game in town on the warehouse side which makes things more tricky.)
E.g. At their current attrition rate they will run out of workers in the whole country in a couple of years assuming they keep it up.