I don't necessarily hate dual bars. What I do hate is burning all my ultimates or potions or whatever to take that last chunk of health off to secure the kill. Realizing I now have to kill the boss again yet without those extras, is what kills me.
Came here to say this, their implementation for his extreme measures modifier is ideal. Every other boss has all sorts of cool new moves, but the final boss is doing absolutely nothing new through the first two phases, then takes a knee like always. You might start to wonder if it's malfunctioning for a moment, then that guitar tells you loud and clear that you're about to get fucked hard.
Spider-Man 2 has a cool thing where every single boss has at least 3 health bars technically. You beat it the first time and then a cutscene, then you beat it a second time and you get a cutscene, and then you beat it for a third time and you again get a cutscene.
The final boss is especially annoying, where it does that same thing but just 10 times (no joke).
The fights play out pretty similar too, which doesn't help.
Spider-Man is one of the few games that I loved the long drawn out battles in, they made the combat in those games so much fun, and it made it feel like a proper comic book superhero fight.