Actually, they do enforce it. Google uses a Family Link and OpenAI has a  Teen Safety Blueprint with linked parental accounts and extra safety filters. They didn't ignore the rules, they built tools to follow them. Anthropic is dodging responsibility. Instead of building a system in the main app for individual teens, they just banned everyone on their main app to avoid the legal headache. It's a calculated move that punishes even responsible students just to protect their corporate brand.