I subscribe to the theory that Starfleet created the councilor position because of Kirk. The job isn't so much a therapist as a political officer that monitors the crew to make sure they don't break the Prime Directive. Troi's position on the bridge and Picard consulting her makes a lot more sense in that light.
I tend to agree with this. Just one example which springs to mind is the scene in “We’ll Always Have Paris” where she takes the captain aside and expresses her concerns about the spike in his emotional response after he heard Manheim’s name, and warns him not to let whatever it is (she doesn’t actually
know why he has this sudden reaction) affect his judgement in dealing with the situation. Scenes like this, IMO, give perfect justification for why she has got a chair on the bridge. In terms of the scripts she rarely got to do anything particularly useful. But in terms of her place in the hierarchy of the Enterprise crew, her
position, then sitting next to the captain on the bridge was quite logical. One of her chief official responsibilities is clearly to monitor the captain and make sure he maintains discipline during those situations which might cause him stress and anxiety, as well as providing him with a comfort zone, somebody he can ask for advice when ever he is called upon to make a tough command decision.