For anyone who’s willing to spend ~15 mins on this, I’d encourage you to play TechDirt’s simulator game Trust & Safety Tycoon.
While it’s hardly comprehensive, it’s a fun way of thinking about the balance between needing to remain profitable/solvent whilst also choosing what social values to promote.
It’s really easy to say “they should do [x]”, but sometimes that’s not what your investors want, or it has a toll in other ways.
Personally, I want to see more action on disinformation. In my mind, that is the single biggest vulnerability that can be exploited with almost no repurcussions, and the world is facing some important public decisions (e.g. elections). I don’t pretend to know the specific solution, but it’s an area that needs way more investment and recognition than it currently gets.