Nothing patronizing about that
Edit: meant as a response to sibling comment
I find 35 young. Young != not adult.
Having a successful nationwide bookclub does not stop her from (apparently) being a content creator. And vice versa, being a content creator does not diminish the success of her bookclub.
You seem to suggest that being a content creator is somehow "less worthy" than having a bookclub. Many people are super successful being content creators on YouTube. Are they less because they don't run a bookclub?
Sounds pretty elitist to me
Edit: bawolff said it better than I could
In this case "Young content creator" can have the implication that she is not a real success but is only impressive because of her age. Since if she was on the level of a real media personality there would be no need to add the "young" adjective. She would just be a "content creator"
Similarly, content creator can have the implication you run a blog or get your fame solely from social media instead of being good enough for more traditional venues (which could be true, i dont know this person).
Is all that massively over thinking this? Probably. But i understand how the phrase could be seen as patronizing even if literally accurate.