Given that these figurines were being produced for over 10k years with a global distribution, I'm gonna go out on a limb and suggest that multiple mutually exclusive interpretations could have been true in different places and times.
And, hell, Barbie. In the last 100 years, we have observed a doll in the form of an adult woman go from being successfully marketed to adult men, to being successfully marketed to young girls. Why would we assume these Venus figurines had a single purpose?
Emphasizing the fertility in the statues is a reason to believe that they could have been intended for use in some rituals or as good-luck charms, but it certainly would not have been a reason to censor their use by children who would have been habitually exposed to nudity, unlike today.