EDIT: Enshittification, also known as platform decay, is a process in which two-sided online products and services decline in quality over time. Initially, vendors create high-quality offerings to attract users, then they degrade those offerings to better serve business customers, and finally degrade their services to both users and business customers to maximize short-term profits for shareholders.


I’m not going to try and pinpoint a specific year, but my off-the-cuff answer is 2015.
It’s just a rough estimate, so 2013 is in the ballpark.