To add some fyi... a lot of Qt experts recommend you restrict the usage of Javscript to the QML layout of GUI controls and data binding. For business logic (especially cpu-intensive tasks), use C++.
Even then, you have great bindings like PySide (for Python) that allow you to build Qt apps without resorting to C++. And it will still be snappier, and easier on disk and RAM, than Electron.
Example of that "avoid Javascript" advice:
deep link: https://youtu.be/vzs5VPTf4QQ?t=30m55s