Is it better to use Android System Webview when not using Chrome as default browser? I've a phone and tablet running Android 7.0. In both cases I do not use Chrome as my default browser.

I believe that the use of Chrome Webview was to reduce resource use by sharing code.

Does it make sense, when one is not using Chrome, to disable Chrome and use Android System webview as default?
From Nougat onwards Chrome is web view. It replaces web view and web view is not available on Play Store as an independent app to install / update separately. In other words, web view is integrated with Chrome


Google Chrome to Replace WebView in Android 7.0 Nougat 



  ....WebView component will actually become a part of Chrome to bring in more data and memory efficiency.



Google explains how Chrome will become WebView in Android 7.0



  ....Starting in Android 7.0 Nougat, WebView will actually be Chrome....The standalone WebView APK will no longer be updated via the Play Store as long as the Chrome rendering remains enabled on your device.



From Android developers



  You can choose your WebView provider by enabling Developer Options and selecting WebView implementation. You can use any compatible Chrome version (Dev, Beta or Stable) that is installed on your device or the standalone Webview APK to act as the WebView implementation.


But webview is not updated anymore nor available , 
so using Chrome is the way forward.

You can also try Chromer a lightweight open sourced Chrome which is less resource hungry