[pas]

They are big, because they invested every penny they made into getting big. And those pennies are converted through human misery in "fulfillment centers". (And AWS on-call is not that fancy either for engineers, though the two are almost incomparable.)

They got some parts right, some parts awfully wrong, and some are just irrelevant now. They make money, they are cheap + convenient, and that usually what people focus on. They are not sophisticated, they are not great designers, etc.