I didn't play with Sims 3 at all outside of a little bit of Base Game (just couldn't get past the graphics, which is on me), but from what it sounds like that game was wide but shallow in terms of feature sets in packs and this one is narrow but deep, if that makes sense.
Mind you, I'm not talking about all that was included in Sims 3 BG as that was both wide and deep (especially compared to Sims 4 BG when it was released, yikes), I'm mostly talking about the expansion packs.
So we got a pets pack with all different sorts of pets which was awesome, but your horses didn't have a bunch traits and skilling like they will here. We got a supernatural pack with a bunch of different types of creatures, but each one didn't have a ton of depth.
It's a totally different approach and I think if you're used to one it's going to be difficult to adjust to the other, which is I empathize with. The good thing about this narrow but deep approach is that you can skip packs if they don't fit your niche because it's less likely they will overlap with things you want.
