It will turn into what eBay turned into: Cheap, misrepresented crap. Web design used to be a reliable way of judging a stores product quality, but less and less every day.
So happy to have a real term for this! I've always just said "A known metric is a gamed metric". Everything from "if you can't touch your toes you're unhealthy" to "price per square foot maximizing" in real estate... once a group has consolidated on a metric and let that metric be known, that metric is useless.
https://en.m.wikipedia.org/wiki/Goodhart%27s_law