The fact that so much of the story is apparently (according to comments) left over to the in-game journals to explain, with the cutscenes themselves only hinting at some of it (if even that), is to me an obvious case of Dark Souls inspiration gone wrong. The problem there is Dark Souls is not a cutscene heavy game like Bayo 3 is. It's designed around that particular method of storytelling (weather or not you like that is entirely subjective). Bayo 3 has no such excuse for not giving these details in cutscene.
You didn't need to read the journals in Bayo 1 or 2 to understand vital story elements, everything you needed to know was given to you. What the journals did was add to the world building which in turn enhanced the story, they were not used as a crutch like Bayo 3 seems to have done so they could just pack the cutscenes with spectacle and not bother explaining shit. I'd compare the journals in Bayo 1 and 2 more to the Datalog in Final Fantasy XIII, adding to the story but not being necessary to understand it.
I did actually like that Viola is (for the most part) obviously out of her league and is simply trying to act like she's way cooler than she actually is. Though a lot of her dialogue (and her design) is still cringey, she's endearing enough but she doesn't get nearly enough focus given that she's being built up to replace and iconic protagonist. We just see her fumbling for an entire game, but we're supposed to buy her as a worthy protagonist for future games. Yeah no!
It's like they wanted to repeat what capcom did with Nero but didn't understand why that worked. Nero was the MAIN focus of DMC4 and the one who ultimately saves the day at the end, even if Dante had to clean up some of his mess (showing that Nero still had a long way to go). THEN they did DMC 5 in which Nero grows into a true equal for Dante and Vergil, so it actually feels like he EARNED that passing of the torch where Viola certainly did not.
To top it off, as much of a spectacle as the final battle is, there's a lot that goes on in it that just doesn't make any fucking sense. It comes off very dues ex machina heavy, which was something the 1st and 2nd game had managed to avoid as everything at least made sense in context. Not helped by Singularity just being a boring villain in general who we know next to nothing about, including how he's so powerful in the first place. The villains of the 1st and 2nd game were literal Gods, how the hell is this joker so powerful?