Yes, BG1&2 were overall lighthearted adventures with a lot silly stuff. But it treated material with straight face. BG3 is in on the joke, even when things are serious, bloody and dark, it doesn't treat it seriously. I don't like it. If it doesn't care about its characters, it's world and story, how could it possible engage others? It is just bunch of nonesense with comicly high, yet unexisting stakes and no personal investment coming from anyone.
To me, Baldur's Gate and Baldur's Gate 2 are both fairly balanced in terms of overall mood. Nevertheless, I otherwise agree with your assessment.
