Bubblelord said this so this may be the case of an unreliable narrarator, but he did say it, Savin never corrected him, and being a lead writer he has to have some knowledge of the lore and power scaling
In his words, Kas is "strong" but she's not God levels of strong, her danger comes from being able to corrupt the world. Gosh help me if Lumia actually does become our sloppy seconds in the romance path because Kas did say she wanted to do that.
But that's a power fantasy, Savin and the writing staff despise those. But in all seriousness, no matter how cool that is, the writing team made it very clear that deicide is off the table. You can beat them at games such as Nareva's thought battle, but to actually go Kratos on all of them, you'll never reach the power to do so. And knowing how much they hate corrupt content, you wouldn't get the option to either.