Roblox lost $70 billion in market value because its own recommendation algorithm started sending kids to games where they spend less money. The company blames a lack of viral hits. The earnings call tells a stranger story. In summer 2025, Grow a Garden and Steal a Brainrot pushed the stock above $130. Those games monetize hard and fast, and kids churned through them spending the whole way. Then Roblox retuned its discovery algorithm to optimize for long-term retention. The algorithm obeyed.…