I am a Linux desktop user myself, so I have some sympathy for Qt, GTK and software distribution via package managers. Nevertheless, as a developer I like the web better, as that is a platform which allows me to easily distribute my applications to anybody on any platform within seconds.

Performance on the other hand is a topic by itself. The problem I see with web applications here, is that it is much easier to create a bad performing program with web technology than with compiled languages and toolkits. But that is something you can learn and if you create some performance critical software, easy distribution might not be your top priority.

[1]: I mean I have seen GTK rendered on a html canvas some years ago, but as far as I know nobody actually uses that kind of tech.

But apart from that, you're right: the main reason for Electron's popularity is the fact that increasingly more programmers know JS quite well whereas desktop libraries seem less and less relevant each year, which makes me very sad.