Graphical frameworks -- GTK? QT? These are intertwined with the language and GTK especially does not look attractive on macOS and Windows. The appeal to HTML

Graphical frameworks -- GTK? QT? These are intertwined with the language and GTK especially does not look attractive on macOS and Windows. The appeal to HTML/CSS/JS is it's 100% agnostic to the platform, and can even be used as a front-end to a program written in a different language.