Yeah I replayed BG1 not too long ago and just about every dialogue selection has a sarcastic, funny or silly response. Far moreso than BG3
The keyword here seems like "response," as in "possible response for your character to make"...? If so, then I wouldn't say that makes the game humorous; it just gives you the ability to roleplay as a silly PC.
It definitely makes the game more humorous, whether you pick those responses or not. In my opinion it would have had a lot to do with the success of the franchise. In the same way that the characters in Critical Role face unfathomably difficult situations but certain characters in particular use humour to keep things light and relieve the tension. To me, that’s a staple of D&D and something I feel is largely missing from games like the Pathfinder adaptations.
