I agree but given it is Kojima, it won't be anywhere as Anthem or a Fallout 76.
Those dark beings are supernatural entities that regular grown adults aren't very adept at sensing. It is said and this is something passed down from thousands of years ago that as babies we are far more adept at sensing the supernatural but most of us tend to lose that ability as we age. However, don't ask me why they have to hook the baby up to some kind of portable embryonic chamber because I am as confused as everyone else here.