IMHO, I love character death in stories. When a character has fulfilled their arc, killing them off is a great way to increase the audience’s sense of investment in the remaining characters. Now, everytime they get in danger, you feel a little anxiety on their behalf because you know that this author is WILLING to kill off characters.
IMHO, Game of Thrones and Walking Dead were both overrated shows (not that they were bad, just that they weren’t as AMAZING as their rep). But one thing both did VERY well is use character death to raise the stakes for the audience. If you hadn’t read the books, Sean Bean’s death or the Red Wedding in GoT made you hold your breath a little everytime a character you liked was in peril.
Killing characters off also helps prevent a mistake that I think ALOT of long-running storytellers have. Not knowing when a character has lost their narrative purpose, and keeping them around to suck the oxygen out of every story going forward.
I’m thinking of a not so well known example where in season 1 of a show, a particular character was meant to be the romantic ‘will they/wont they’ character. But then the show changed it’s mind and decided that both characters were too decent for there to ever be good drama from their relationship (which was a shitty reason, but let’s ignore that for now).
The mistake is that because that actor was part of the cast, they kept him around for 4 seasons after that in which he was complete narrative deadweight. They tried to force his square peg into a few round holes, but they could never find a narrative purpose for him after that. He was a drag on every scene because he was just there to consume oxygen and say lines. He should have been killed off or ‘moved away’.