I don't have open world fatigue. I think I'm immune to it. You give me an open world to explore with interesting aesthetics and a bunch of collectibles and objectives and I'll easily sink 30+ hours into it - what really annoys me, however, is how so many developers fail to realise the potential of open game worlds and instead prefer to fall back on having an epic, cinematic, film-like storyline that makes up the meat of the experience. If more developers or, hell, even one developer attempted to make an open world that's driven by player choice and action rather than merely serving as a backdrop from some sub-Hollywood level bullshit plot, it'd really help move the genre along in a significant way.