The problem with killing a Glenn is it breaks your main characters, imo. There's just only so much punishment we can watch characters take, and if you get to the point where you think "I don't care how it happens, I just want these characters to stay alive," then you're at a point that isn't very interesting from a story perspective.

A character still needs to have hopes, dreams, something they're actively pursuing. Once you make shit hard enough for characters, we realize that these characters probably don't give a fuck about the things that define them anymore-- they're now just broken people trying to find any reprieve from pain. And we don't want them to pursue anything anymore, because we fear they'll just keep getting hurt. Once you're there, you've hit a wall in your story.

Game of Thrones worked even when they killed great characters because the surviving characters still had objectives, goals to pursue. The closest they came to fucking up-- and it generated huge amounts of backlash at the time, IIRC-- was the Sansa stuff, because for a couple of seasons, she was just getting passed off to rapist psychopaths. She had little things in there where she'd learn or show herself, but the core of the character for a season or two there was "try not to get raped/murdered by your husband." And that's just not that interesting a story to tell, watching someone living in fear, trying to not get raped. Once she had more agency, she became infinitely more interesting and her story far more watchable.

There are plenty of shows/movies where we watch people suffer for long stretches without the show/movie breaking who they are down to the point of "who cares, just stay alive." Cast Away is an obvious movie example of this. I'd argue the flashbacks of Yellowjackets mostly succeed in this regard as well. Take away things that matter to them, push them to the brink... but you can't ever get *that* close to getting them past the brink. An audience'll tap out.

You can kill "good", beloved characters and still have the audience stay tuned in. You just can't leave your survivors broken.

That's how I feel, anyway.