Today, the super-wealthy have a megaphone for their worldview that is orders of magnitude more effective than anything anyone else has got. It's not just Thiel: Bezos, Soros, Musk, Paul Singer, and others all are or have been promulgating their worldviews at a scale formerly reserved for nation-states. If unchecked, this inequity will bring us to a world not dissimilar to Byzantine Europe, where the "word of god," as filtered through your lord of choice, utterly dominates the marketplace of ideas.
You're not wrong, but the same megaphone applies to the average Joe. In the early 1990s, unless you were a celebrity or politician, your ideas could not spread beyond the confines of the next city council meeting - at best. Now an average person has far more reach. Yes there's often a cacophony of other information that will drown you out, but it's hardly worse than the previous situation where all media was in the hands of very few, often very wealthy, individuals.