Reddit CEO Steve Huffman stands on the floor of the New York Stock Exchange (NYSE) after ringing a bell on the floor setting the share price at $47 in its initial public offering (IPO) on March 21, 2024 in New York City.Spencer Platt | Getty Images News | Getty ImagesFor 20 years, Reddit has pitched itself as "the front page of the internet." AI threatens to change that.As social media has changed over the past two decades with the shift to mobile and the more recent focus on short-form video, p...