Browsers still can not access the filesystem correctly, can't communicate with most of the devices you could plug into your computer, can't reasonably use keyboard shortcuts and so on.
But the native version already does that! What can electron do that the native version cannot ?
The point of electron is that it let you write code once (in JavaScript or something that transpile to js, like TypeScript or Elm) and built multi-plateform software. But if you have a native software that can be built in wasm, it also can be built on Windows + Mac + Linux. Why using electron in that case?
Electron is great if you don't want to write native code (and deal with the debugging complexity of C or C++). If you already have a cross-plateform native app in written with Qt, why the hell would you want to put that in Electron?!
And remind that if your C++ isn't cross-plateform already, you won't be able to build to wasm.
This would of course have to be tested but there might be less overhead? I haven’t used FFI but they mention that it is significant. I have written a V8 add-on using NAN and the performance is very good (as in passing relatively large arrays between C++ and Node is in the few microsecond range)
Electron is great if you don't want to write native code (and deal with the debugging complexity of C or C++). If you already have a cross-plateform native app in written with Qt, why the hell would you want to put that in Electron?! And remind that if your C++ isn't cross-plateform already, you won't be able to build to wasm.