Some electron users are certainly take advantage of the features node.js provides. But others just want a html+js based UI on top of a local webserver written in their preferred language.
My ideal model would be having one piece of trusted javascript which works similar to web extensions which can control the window, trigger navigations, approve or deny permission requests by origins and can interact with the current web control. Any advanced integration with the host operating system would happen though the local webserver (which could be implemented in node.js if that's your thing, or in C#, Rust...). This would not require many changes to a browser runtime.