It's interesting though sad to chart the decline or "enshittification" of these companies. A simple explanation is that when big companies become monopolies, or de facto monopolies (e.g. Facebook & Google have competition but no one is close in scale), they no longer have to care about being customer friendly or "doing no evil" as Google used to promote.

Amazon, Facebook, Google, and others are so big and comprehensive that it's extremely inconvenient to not use them. So they've reached a stage where they don't have to be popular or likable anymore to profit and stay on top.