Out of curiosity, I just did a few searches along the lines of "is MSFT/FB/GOOG bad place to work" and for each of them there were several results/websites about how each of these companies is the worst place to work. If you look at the largest publicly available data set, Glassdoor, AWS does quite well - better than Microsoft and as well as Google. I have not worked for Amazon outside of AWS, so I can't really comment on that. However, as Amazon has more than 1,000,000 employees (400,000 of which were hired in 2020), I'd argue that you get more negative stories simply because of the larger population? Comparing Amazon to MSFT (163,000), FB (50,000) or GOOG (135,000) without taking its ginormous scale into account seems to be comparing apples to oranges. In terms of scale and typology, it would probably be better to compare AWS to these companies and I believe that the publicly available data paints a different picture than what you describe.

I'm not trying to argue with you here, I've just had a quite few discussions in recent times with people who had very strong negative opinions about MSFT being a place for the lazy, Google being a place for the special snowflakes, Facebook being a place for the cultish, AWS being a place for those looking for a stepping stone in their career, etc....and I think that all of these companies actually are great places to work but there will always be a few percent who absolutely hated their time there.