Kronika definitely didn't feel like the "big bad" in this game at all. I know that is what she was supposed to be, but Kronika just felt "in the way". I really liked that Dark Raiden and revanant Liu Kang were on opposite sides, but Dark Raiden went off the radar after Kronika emerged timelines in the original MK11 story. And here's why she was in the way: most of these events could've played out the same way and the same story could've been told without Kronika. I mean, they could've had revanant Liu Kang and Kitana discover the Keep in the Nether Realm and use the hourglass and the soul crown to attempt to erase Raiden from history, destroy the realms, and recreate history as they saw fit. They basically do what Kronika did, which is bring back warriors from the past including their own selves. And we still end up with the same original ending. Kronika was not needed.
Only way I see Kronika being necessary is if she is what Shang Tsung was to MK1, which was him working for Shao Kahn. Maybe she's working for another titan (One Being). I mean, even though she's a titan, she was just a keeper of time and needed the crown and goons to fend off mortals, didn't forsee Raiden combing with Liu Kang or the events of Aftermath.