No hate but killing characters off just for shock value always was cheap as hell. But Game of Thrones made it popular so now every writer thinks he's a genius for "subverting expectations"
Yeah I mean I get the whole “real like is not that merciful” argument but this is writing and when your going to make a Charcter die make it for a good reason. There are 3 better reasons to actually I can list: leave an impact on another character/s(physically or mentally), impact on the plot (to progress it specially), or to reveal something/make a point
Imho, the character deaths don't feel like shock value, they're more like "Gege runs outta ideas on what to do with them so why not have them killed while the moment makes it possible"
Honestly, this might be true. Apparently Gege wanted a more straightforward horror story before his editor pushed him into adding Shonen tropes like putting it in a school setting and such