Article from credit.com discussing how and why some leading issuers are discontinuing price protection as a benefit on their cards. It appears that a major reason for this is that price protection is not really a high priority for most customers as opposed to low APR, cash back and no AF:
Price protection means that if you purchase a product and the price goes down within a set number of days you are refunded the difference. I suspect that this is expensive and difficult to manage "perk" which is why some issuers are discontinuing it. I know I've never used it, but I'm sure it has been abused/used by some.
A lot of it is bots. People allow apps to scan their emails, and the apps identify purchases and file the relevant claims. The app takes a cut of any savings and it's all automated.