Earlier quoted context omitted.
There isn't anything about Electron that I feel it is simple over Delphi, WinForms, JavaFX, Android, Cocoa, Qt, XAML, other than being easier for those that grew with HTML/CSS.
Caveat: It's been a long time since I've used GUI toolkits like Gtk+ and QT, so this may be an out-of-date perspective. What I think of GUI toolkits, I think of lots of imperative code to build out an interface, e.g., "Create a window. Add a vertical box layout. Create button1. Change button1.font to xxx. Change button1.style to bold. Set the minimum height of button1 to 20px. Add button1 to the box. Create button2.…
Qt always had a nice UI designer, with layout managers for responsive UIs, no need for imperative code to build out an interface.
Since version 5 they have QML, a JavaScript like declarative language, quite similar to J3 the first version of JavaFX.
Usually imperative UI code tends to be a thing only among developers that dislike RAD tooling, or game devs using immediate mode UIs.