No other dolls offer such potential for realism as baby dolls. For one thing, no other dolls are so similar in size to the real people they depict.
A baby dolls and reborn dolls are almost the same size as an actual baby. Even a large 18-inch play doll is on a much smaller scale than an actual child is.
Details on the face, body, and clothing of baby dolls are much truer to life than other dolls, which must inevitably stylize and simplify some details.
Indeed, even sometimes the line between baby clothes and baby doll clothes can get blurry, or disappear altogether.