I appreciate others want a different ending but there is a point to where it just gets untenable.
I think it bears taking into consideration that:
1. Her quest feels very short and un-interactive (a fetch quest for two pieces of material and an interaction with a character you're going to be interacting for the main quest anyway - compare that to Shadowheart or Lae'zel who have literal locations for their development alone).
2. Her quest and her 'problem' also severely lack any forks in progression or proper player's input - we can't do anything major, we can't really challenge anything, and the final choices are generally always the same. We can even skip her upgrades completely and that won't change anything about the endings available to her. Again, compare that to Astarion or Shadowheart.
3. There's an abundance of options that directly refer to her situation in-game, in canon text, but we're not allowed to interact with those opportunities in any way, which makes the "We did all we could" conclusion of her quest sound extremely out of pocket. We did nothing, in fact. We weren't allowed to. Which feels incredibly immersion-breaking in a game where we can approach most problems (personal or not) from different angles.
We are not hoping for another option just because. There's a lack of content when compared to the other main Origin characters (excluding Wyll who actually got even less timing-wise and scene-wise - and even so his quest can't be that easily skipped!), there's a lack of player agency and there's a direct feel of missing a piece of a quest because of all the dangling threads. It's not unreasonable or mean on our part to hope for Karlach to receive the same treatment the other characters do. Which would include being able to actively and substantially alter her fate like we do with most others, instead of being so passive that we could literally not speak to her once and get the same result.