I think one of the main issues I had with Rage was that the game world wasn't very compelling. It felt kinda barebones and generic.
In a crowded market FPS games kinda need a hook to standout from the crowd, be it the atmosphere, storytelling, and plasmids of Bioshock, the insanely over-the-top "you are the ultimate killing machine" focus of Doom 2016, the scope and destructible environments of Battlefield, or the grittiness of the pre-PS4 Killzone games.
Rage didn't really have that special something.
I'd say that the world design was a hook for Mad Max fans, it is very similar.