The problem with this spell on BG3 is that mechanically, all it does is to block actions on a failed save, while they're inside the cloud.
It does nothing against their movement, and the moment they step out, they can attack you.
On the table top game the spell also says:
"On a failed save, the creature spends its action that turn retching and reeling."
Which sounds to me that they basically waste their turn retching and reeling.
On BG3 the npcs will jump out or run outside of the cloud and then attack you on the same turn. They can also misty step out of it because also mechanically, it's not an action, but a bonus action.
So in short, you waste a lvl 3 spell slot and turn to maybe make enemies use their movement and/or misty step.
PS: Stinking Cloud is also heavily obscured on the table top and it is not on bg3 > Sleet storm has the same issue. It's not heavily obscured on bg3.
