One thing that people for some reason don't like to voice out loud: America won this way. Maybe it has become politically incorrect to even voice anything positive at all, like doomerism grasped all sides of society?

Baath party is destroyed and no longer exists, political and underlying ethnic groups that propped it up are deeply marginalised and sidelined, political regime in place in Iraq is exactly the one America wanted to have there, and it WORKS: they have regular competitive elections (in the strictest sense of it: before the elections, no one can predict results in advance) and a well-functioning civil society where people can advocate for, or protest against things without it devolving to tribalism (not "Shia vs Sunni" riots or similar). Iraq as it currently is, is created by America and stands firmly on its feet.