Aside: Would love to see electron and Cordova bridge the gap together for mobile targets. If they can establish a few common interop libraries, you could come very close to the same code for both.
I'm really uncertain about a huge JavaScript runtime on mobile -- seems like an energy waste/slow code. Dart's AOT story the Cupertino wrappers for iOS in Flutter really excite me.
Disclaimer: I work for Google; all opinions are my own.
The runtimes is already there. Not to mention there's still room for improvement.
I'm not against other options being available. But there's a certain amount of pragmatism to being able to use the same skills, developers and code to approach development that targets several disparate platforms in a very open way.
My favorite language is JavaScript for all the flexibility. My second and third are Rust and C#. Just getting my feet wet with rust and have done C# from the beginning. They all have very different reasons to exist and most applications can be written with any of them.
In the end of the people paying for the development cannot fund a given approach, there's a certain pragmatism that must and should take priority.
With JS I can use functional, classical, and procedural approaches and mix them as needed. There are foot guns. They are there in every language.
As to overhead and battery, I can see the point. If rather have an app with more overhead, than no app at all. I use Windows, Linux and Mac and tend to favor apps that work everywhere. If like to see that extended to phones.
