I'm not fully sure how they work, I assumed that they would affect autonomy and what sims are doing but it doesn't seem to affect them too much, at least not with some likes/dislikes, sims that dislike making jokes sometimes seem to make jokes anyway and then they look annoyed at themselves or sims that don't like working out are spawning at the gym and are uncomfortable...
I think they could have tuned it when it comes to things like music and decor too, a sim shouldn't get uncomfortable from just hearing music that they don't like in the background and they shouldn't get tense over one decor item that they dislike, but if they listen to the music or if there are multiple decor items then I think they could get tense.
I do like that they get added fun from doing things they like, fun is the most difficult need to fill in my opinion, I don't want all my sims to play videogames and watch tv or wohoo all the time.
I do like them since they are a way to give ours sims a bit more personality and I hope that they will add more likes and dislikes and that this will affect more what they are doing when we are not controlling them and where the game spawns them as unplayed sims on other lots.