I might be totally off base here, but I get the sense that native widgets have become a skeuomorph for following the common UX conventions of the platform you're running on, with the latter being what brings the real value. The equivalent conventions for web apps and their desktop derivatives are much looser and don't yield as much consistency on which to build effective user expectations and habits. People who experienced the shift can tell something is missing, and the most obvious correlate is the disappearance of native widgets.