I won't spit on the sims 4 CAS because the level of customizing detail is awesome compared to TS3 just like the new building system which is far more easier to handle and customize.
But besides that, there is nothing attractive about TS4 especially when it comes to the fun. TS4 just lacks too many features to get me addicted. I can play hours on TS3 while on TS4 I am bored after 30 minutes of playing. No Open world, no toddlers, no pets and when you add CC, it's conflicting with the game. I had to remove them all when the pool were finally added to the game and that was the last straw. So to me I dont even have to think twice about which is my favorite: It's Sims 3 hands down.