Vietnam’s digital economy is increasingly smartphone-first: everyday activities such as messaging, payments, shopping, transportation, and public services are mediated by mobile applications and platform ecosystems. At the same time, personal data processing has intensified through app permissions, device sensors, background data flows, and cross-service profiling. Most contemporary privacy regimes rely on user consent as the primary legal and ethical basis for processing. In smartphone-centric ecosystems, however, consent is frequently reduced to rapid acceptance of permission prompts and privacy notices that users rarely read, understand, or can meaningfully negotiate. This paper develops a conceptual and contextual argument that consent-based data protection is structurally insufficient in smartphone environments, not because users are irrational, but because mobile ecosystems embed asymmetries of power, opacity of information flows, and design patterns that convert consent into an illusion of control. Using Vietnam as the focal context and drawing on interdisciplinary insights from information systems, digital governance, and privacy theory (including contextual integrity and user agency), the paper proposes a shift from consent to control: a governance logic emphasizing ongoing user manageability, system-level safeguards, and platform accountability. The paper synthesizes literature on mobile permissions and consent fatigue, analyzes key regulatory developments in Vietnam (with particular attention to Decree 13/2023/ND-CP), and outlines a control-oriented framework that links ecosystem design, governance instruments, and user capabilities. The contributions are threefold: (1) reframing personal data protection in smartphone-centric settings as a control problem rather than a consent problem; (2) articulating a Vietnam-specific contextual agenda that highlights enforcement and ecosystem dominance issues typical of emerging economies; and (3) offering actionable policy and design implications for regulators, operating system providers, and app/platform operators.