I don't know if/don't think that Qt's licensing is an issue for most of the people who need to make cross-platform applications and reach out for Electron. Electron seems to be the default choice not just for FOSS projects, but also for commercial projects, which have no qualms using a toolkit that might go proprietary, and can get a commercial license if they need it (which most of them don't).

GTK, on the other hand, yeah, it hasn't been a good choice for cross-platform development for years now. The only platform it properly supports is Gnome.

I definitely started out as a strong gtk advocate. But these days I wouldn't have qualms about using QT if it were the right fit for the project.

I'm not sure I'd be down with it if every application become an Electron one. But the browser does have some significant benefits since the people who make the browser did all the heavy lifting for you.

Chromium started out using gtk2 and then switched to Aura? Do any projects use aura directly?