Unreal Engine is broken, why do people use it and like it?

I understood that Modular game plugin is to inject new functionality into the base of a game without having to touch any of its code. (Seasons and DCL), as if you were making a mod of your own game, but having access to everything.
I don’t think you can make a lot of agnostic modules to reuse between projects if they have different gameplay.
And without animation blueprints, where do you manage that the animations, the Anim state machines, the control rig, the poses are synchronized?