Historically, babies were surrounded by parents, grandparents, aunts, uncles, siblings, and cousins who all took care of them. The current US societal norm of two parents attempting to raise children without everyday familial support is a historic anomaly. Even in the US, some subcultures have closer family ties with relatives taking care of the babies every day. Older siblings often take care of their youngest siblings, acting as pseudo-parents because their bio-parents are distracted with other tasks.
Babies just soak up the love and attention.