Imagine one platform hosting a lab preprint and a celebrity clip. My opponent says shared algorithms make boundaries meaningless. But boundaries aren't walls; they're role-specific standards: science needs falsifiable evidence, politics needs public accountability, entertainment needs disclosure. Same infrastructure can still apply different rules, like roads carrying ambulances and delivery vans under different protocols. If engagement logic overrides those standards, that's exactly the failure boundaries prevent. So my opponent's strongest point, that one engine optimizes all three, actually argues for enforceable role distinctions: labeling, provenance, and transparency. Bridges, yes, but with guardrails.