Great example: 15 years ago, assuming you were out of contract, cancelling a postpaid cell phone line worked very differently. Important to know: it was and still is “billed in advance,” meaning you pay around say, January 4, for your service from Jan 4 through Feb 3rd. So if you cancelled your service around Jan 19th, you’d be owed a refund of a half month’s service. 15 years ago, you’d receive a check or a credit to your method of payment - since you didn’t get the service you paid for, that seemed very obviously correct. Sometime at least 10 years ago, one of the cell phone carriers decided to try just saying that you never got a refund, and that if you didn’t want to be ripped off, then you should just cancel on the one day of the month where you had finished using the service you paid for (and hope you didn’t do it too late and get billed for another month). Initially it was just that one carrier who did this, but quickly this became the norm across the whole industry, and now all three postpaid carriers work exactly that way.

This is of course the same story with more well-publicized enshittification, like Basic Economy plane tickets, data caps on your broadband service, etc. etc.