Actually I find the consistency and simplicity of using well established, widely supported and rich third party ecosystem available with using HTML5/CSS/JS base

Actually I find the consistency and simplicity of using well established, widely supported and rich third party ecosystem available with using HTML5/CSS/JS based UI very liberating vs. the incompatible mess of native UIs. Personally I script all front-ends in web technologies irrespective of platform and back end tech. The browser rendering engines and JS engines are reasonably fast in most platforms.