React Native's hallmark lies in its facilitation of cross-platform development, streamlining the creation of apps operational on both iOS and Android devices via a unified codebase. This not only slashes development timelines and costs but also mitigates codebase complexity and maintenance overheads. Furthermore, React Native ensures alignment with the latest platform features and updates, integrating pivotal enhancements from both the iOS and Android ecosystems seamlessly. 

Another cornerstone of React Native's appeal is its capacity for expeditious development. Leveraging JavaScript, a familiar language for many developers, fuels a swift and efficient creation process for native mobile apps. Bolstering this advantage are JavaScript's extensive libraries and tools, augmenting functionality and productivity. For instance, Redux simplifies state management, while React Native's hot reloading and live reloading features facilitate real-time visualisation of changes without the need for app rebuilds or restarts.

React Native thrives within a robust ecosystem buoyed by unwavering community support and Facebook's backing, making it a titan in the tech realm. With a vibrant developer community at its core, React Native fosters collaboration, feedback exchange, and resource sharing, bolstering the framework's evolution. Moreover, extensive documentation, tutorials, and resources abound, nurturing a conducive environment for learning and mastery.

Performance optimization emerges as another cornerstone of React Native's ascendancy in mobile app development. Employing a virtual DOM expedites UI updates, enhancing responsiveness across devices. Additionally, React Native capitalises on native device capabilities like GPUs and CPUs for graphics rendering and animations. The integration of the Hermes JavaScript engine further refines performance metrics, optimising startup times, memory utilisation, and app size. 

React Native empowers developers to harness native device features seamlessly, including cameras, microphones, GPS, accelerometers, and push notifications. With a suite of native modules and components, developers can interface effortlessly with platform-specific APIs, delivering an authentic user experience. Furthermore, React Native facilitates custom native code integration in Objective-C, Swift, Java, or Kotlin, enabling complex functionalities to seamlessly mesh with JavaScript code. 

Lastly, React Native embodies versatility and adaptability, catering to diverse app domains and purposes spanning e-commerce, social media, gaming, education, and beyond. Its compatibility extends across various app types, from web apps to progressive web apps and desktop apps, fostering integration with complementary frameworks like React, Expo, and Electron. Armed with a modular, declarative architecture, React Native empowers developers with the freedom to customize and scale apps as per unique requirements and preferences.