Are you saying that the webviews for some reason feel less native in the newer OS versions, or that the latest native OSes are so fast that the webview's shortcomings stand out more?
So PhoneGap applications are technically "hybrid apps." The WebView portion of the app is native code - but that really is just a technical nuance with no implications for performance (in fact, the performance implications are negative), because it's like claiming that your website is "native" since it runs in a browser (say, Safari) and the browser is written in native code. But the non-native portion of the app is what goes inside the WebView (HTML/CSS/JS).