Comment by array_key_first

The metrics are bad. Data driven decision making is a very easy trap. If you capture the wrong data then you just optimize for worse stuff.

Classic example: reactions and watch time as measuring engagement. Leads to shittier content being promoted because the more garbage something is, the more outraged people will be.

And that's why Facebook has "optimized" itself to be as shitty of a platform as humanly possible.