He failed to produce his own brand. The only thing that comes to mind when anyone thinks about Mark is "Facebook scandals", "looks, moves and talks like a reptiloid/robot" and "the mataverse that no one wanted failure (no legs!)". I bet he wishes he would have been what Elon Musk was, someone with pretty much his own cult. Elon Musk still has his cult followers and online knights despite his increasingly erratic behavior and general unpleasantness.