What act3 lacks in my opinion is an overarching theme. The first two acts have this, the third just doesn't.
100% how I feel and 100% what I think the crux of the issue with Act 3 is. So much of what you do throughout it doesn't lend itself to a goal of any kind. It's just "lets run around EVERYWHERE and help random people/improve our image/find clown bits etc."
Ketheric and Moonrise was an omnipresent danger that was looming over a tarnished landscape. Everything felt like it was building up to that area and then the climax felt important and relevant. Everything affected your companions in a significant way.
Whereas, Act 3 we have Orin and Gortash and Ansur and Cazador and Raphael and Orpheus and Sarevok and The Mother Superior all mashed into a single Act. None of these characters get a proper build-up, none of them feel like an omnipresent danger, and every one of their stories ends suddenly with no payoff or reaction from your companions other than "That happened! Wow!...moving on."
