So I'm hoping this also extends to combat, and that gives me a good comparison. In Dos2, even with only 75% accuracy, I got no joy from a hit. I just expected it. In XCOM however, even with 90% chance to hit, I got so happy when I would hit. It really felt like chance played a role in the game and it made it more fun. Plans would always get messed up, you'd have to adapt all the time and it was a lot of fun. I'm hoping bg3 has some of that feeling. It doesn't have to be as tough of course, but I want to feel the effects of the d20 gods. Even though dos2 had some chance to it, it never felt like it.
I think that the degree of tension/dread/excitement (delete as appropriate) in a game with randomised outcomes is directly related to how significant the outcome of an action might be.
My memory of XCOM is that both you and your opponents can do significant damage ( or almost none ), leading to potential 1 or 2 hit kills, which naturally leads to more riding on the randomised result of each action.
Compare this to something like DA:I where the health bars are generally significant ( and damage is not random ), needing many hits to whittle away; each individual action is less important, but they are more of them occuring. Such a game needs to find other ways to generate tension.
That's my pop-psychology analysis of what you are saying, anyway
