The reason "enshittification" works is that there's a lag between when you cut quality and when you start losing customers. In the interval inbetween that, profits skyrockets.

You have businesses like Amazon/Facebook/Google that are de facto monopolies. No matter how much they enshittify their products, they won't lose customers. When they were new and in hypergrowth mode, they had to have a good product to get customers. After they got monopoly status, they stopped caring and focused on maximizing profits.

With Amazon/Facebook/Google there are no serious alternatives. With a restaurant, there's much less switching costs for me. So I walk an extra block to get lunch? They don't have a monopoly, not in the same sense as Big Tech.