I agree, babies have not been spoiled by this world and society yet. Indeed they are pure and honest, they have no words to communicate yet so they just openly show the emotions they have, unfiltered to communicate with their surroundings. And no one really lectures them about it until a certain age and that is when all the restrictions start.
I have a small story regarding that topic: I was talking to a person who works at a mental health facility and who knows most of my story. At some point we were talking about how i dislike babies/ toddlers/ children but stated how i like animals because "they are so pure and honest". I am a quite controlled, stern person, meaning i learned to not show many emotions, i do not cry and all that kind of stuff. The mental health worker asked me what i do not like about them and i was like "they cry too much, they scream around, it is just disgusting and annoying,..." and then she looked at me and told me that that might be the problem. And she did not mean the babies but my behavior/ nature of being strict and stern to myself and always wanting to have control about emotions, me not allowing myself to show emotions as open and pure to the world like a baby does.