India, June 30 -- Leo Radvinsky keeps a low profile for a billionaire at the helm of one of the internet's most lucrative and controversial platforms. His minimalist personal website paints the picture of a modest entrepreneur, angel investor, and aspiring helicopter pilot. But conspicuously absent is any reference to the true engine behind his fortune: OnlyFans, the adult-content subscription platform he transformed into a global digital empire.

Radvinsky is an economics graduate from Northwestern University and has successfully reshaped the landscape of online pornography, shifting it from traditional ad-supported adult content to a subscription-based model that blends social media with intimacy. Under his leadership, OnlyFans has grow...