This is a very good point that I hadn't thought about. The quiz that is taken on the mole is another thing that leaves us guessing while The Traitors tells you who is voting for who at the ceremony.
I think the most engaging difference between the shows though is that whoever is chosen to be The Mole gets an auto pass to finale night and cannot be sent home whereas the traitors are not safe until the end. Yes, the three do have an influence on the game in manipulating the other players and cannot be murdered, but they can be sent home during the house banishment vote.