I'm not sure where you got the "non-private" in nature piece. I took this "identification tool" on the FAA website, https://www.faa.gov/uas/getting_started/user_identification_... , and while yes, if you are, say, taking drone photos to hawk some particular product online, that would clearly fall under Part 107.
But an influencer that's just taking vacation photos, even if it's of their impossibly fashionable vacation and it seems obvious that there is an ulterior motive of building their "brand", seems like they could easily argue they're just doing it for recreation and would thus fall under the Recreational Exemption.
That's certainly a fair interpretation of the regulation - but if one could argue that social media is one's 'job', I would also consider posts on their usual accounts as commercial content. I guess the point is the FAA has the discretion to consider your use how they want, and there isn't much good case law / precedent for this because the FAA largely hasn't been enforcing Part 107 requirements yet.
But an influencer that's just taking vacation photos, even if it's of their impossibly fashionable vacation and it seems obvious that there is an ulterior motive of building their "brand", seems like they could easily argue they're just doing it for recreation and would thus fall under the Recreational Exemption.