Media is an institution, too, and one way to change the media narrative about tech is to build a brand new media. Over the past two years, Andreessen Horowitz has led substantial funding rounds for Substack, the e-mail publication platform, and Clubhouse, the audio-based social network. When customers sign up for Clubhouse, they’re given a list of really helpful accounts to follow, which tends to include several Andreessen Horowitz partners; Andreessen himself has five million followers on the app. The firm has about a dozen Clubhouse shows of its own, including “One on One with A and Z,” hosted by …