ISO 21448 (safety of the intended functionality, or SOTIF) is a new standard addressing safety in advanced driver assistance system (ADAS) and automated driving (AD) vehicles. The combination of ISO 21448 and ISO 26262 (Functional Safety, or FuSa) creates a holistic view of safety for this domain; however, the new perspective on safety embodied in ISO 21448 requires additional work from both OEMs and suppliers. Most of that additional work comes from the need for verification and validation (V&V) methods that can show that the overall residual risk introduced by ADAS and AD systems is acceptable according to an agreed-upon criterion. Arriving at those criteria will require additional guidance beyond ISO 21448; after all, automotive safety standards are strict and ADAS/AD is subject to the open-world problem. This paper seeks to make the case for SOTIF based on probabilistic risk analysis methods and well-established risk acceptance principles. It will shed light on V&V strategies that OEMs and suppliers can use to estimate residual risk.