I don't think it's low effort, it's rather efficient. From my point of view, the problem with Karlach is basically what makes her popular, she is that perfect cinnamon roll from the start. She has not much of a character arc because there is no need for her to have one. You can't even corrupt her because she is too decent for that. She has not much to offer apart from being heart warming or heart wrenching. I think she is wonderfully written and acted the way she is, but there is only so much you can do with a character that does not have any internal conflict.
Really, my only big issue with her ending currently is, that on certain characters, you cannot stop her from exploding in the end, despite going with Wyll being her default decision.
