I don't wanna half-ass something and live in a headcanon whilst everyone else gets their "live long and prosper" ending
As already discussed, there are other games that do the terminal patient tragedy, sometimes with your followers, sometimes with your own character, but usually people can somewhat stomach that enough to finish the overall story. Because it's painful, as it should be, not frustrating. The way for many players Karlach's situation becomes unbearable instead of poignant or whatever is... telling.
Those games are often very linear, games where you follow a set story. This is supposed to be DnD, a game where you carve your own story in the world's setting. And there is absolutely no reason not to have a good ending along with the bad ones. Just let the player make their decision on the matter, and call every possible ending canon to their respective player.
