Also, if you're a cleric, you get the ability to ask for literal divine intervention once in your life at a high enough level. Using that to save someone you care about from a horrible fate seems 100% aligned with how most of the good gods in the setting operate. Again, it's a game mechanic, but if you have a character that can *literally invoke divine intervention* and then tell them "yeah, nothing you can do, problem is unsolvable" people are going to ask questions, heh. Also, it'd give divine intervention a use that doesn't feel really underwhelming, which all the current options do, to me. (though in fairness, this would lead to kind of a snowball effect where there's a question of why you can't use it in literally *any* quest once you're level 10, and that's a can of worms I can understand not wanting to open.)
But as you just said- the craziest thing is the Gondians. If you're a writer and you want Karlach's heart problem to be unsolvable, that's a storytelling choice- I don't care for it, but I'm not the writer here- but if that's what you intend, why in the name of all that's sane would you have people who, from what the game tells you, have already solved that problem- and then just refuse to let the player even try to follow up on it? It's basically a choice *guaranteed* to make people frustrated and unhappy. I know I've said before it's not really useful to speculate on what is/isn't cut content or why certain things were left out, but I would love to know how that particular decision got made. it just feels baffling to me.