I concur, maybe it´s nostalgia talking, but I do not remember BG-BG2 (Tob definitely yes) as a particularly dark and gritty game.
For most it's runtime BGs were not gritty. Thay had some dark content, but overall the feel was of an adventure, with some dark and really silly moments inbetween.
Playing through D:OS2. and what I miss are stakes. No one really cares, nor is concerned about anything. While BG2 was bright and fun, dark stuff happened and had consequences. Things happen to people outside your party, but all Origin characters seem like a bunch of sociopaths.
D:OS2 doesn't shy from gore and gross, but it doesn't have narrative impact. Your companions are constatly snarky and indifferent, and so are most other NPCs.
