I think a lot of MSQ deaths are purely a result of the writers not knowing what to do with the character anymore. Ysayle, I believe, was the first victim of this phenomenon. Her character arc was complete, so she had to die. It's apparently their favourite way of tying up loose ends (yes, I'm immensely salty they did this with the Twelve). This is actually also what happens to a lot of major villains. I thought it would be much more interesting to grab some of them by the scruff and drag them, kicking and screaming, towards atonement but the only case we got any hint of this was Gaius and in his case, it was more like "conveniently forget all the villainous things he's done uwu".

Actually, many deaths in the story are a result of lazy writing - upping the stakes by fridging a character (Haurchefant, the king of Tural) is another extremely common one. And yeah, there are also a bunch of red shirts like Geode but Dawntrail in general completely failed to spark any kind of interest in me, so my reaction to 95% of it was "meh" anyway.