Infants are actually, like. Really good?
I don't play "families" a lot. I play The Sims like an MMO- I make a character, I pick a "class" for them, I focus on that experience, and when I get bored I reroll a new character. But I'm playing "generationally" for maybe the 5th time ever right now.
Aside from their name (Seriously. It goes Baby -> Infant? No. That is wrong. It's objectively incorrect, it's full-on wrong and it drives me nuts) they're so well put together. The way they have to coo before they can babble, or have to be able to lift their head before they can roll over, or sit up. They have to sit up before they can go in the high chair and try solid food. They have to learn to laugh! They can't even have fun or be bored for a while until they develop enough to "need to".
And the quirks are so fun. Mine is an early riser and sure enough, will wake up early in the morning. He's got the pees-while-being-changed quirk and regularly does so, that's so funny. There's so many quirks, too.
There's so many ways to interact with them and their facial expressions are really good, and they even show off their genetics really early. Tell me this kid doesn't have his dad's eyes and scowl.
They're really engaging to play with, I'm really impressed. I know I'm very late on this observation but from a "Playing this game as a standard challenge-overcoming video gamey video game" perspective I'm surprised how much depth and gameplay there actually is here.