SDL is intended for gaming and similar applications, it isn't intended for general purpose GUI development. That's what toolkits like Qt and GTK are for. These toolkits do compete with Electron.
With the disclaimer that I don't know a lot about this: Electron has solid support for both desktop and mobile targets. I don't think Qt's mobile support is as good, but I might be mistaken.
With the disclaimer that I don't know a lot about this: Electron has solid support for both desktop and mobile targets. I don't think Qt's mobile support is as good, but I might be mistaken.