The problem in a framework like GoDot is, that it is meant for Games. A game renders screens in 30/60 fps. A Desktop application like a Gtk application does exactly nothing if you dont interact with the application. If you click a button only the button gets re-rendered. This is more efficient then using something like a game engine which has no concept about damaged regions and so on.

Also, people like to have something like "native" look and feel. This would be possible with Java-SWT as it abstracts away the toolkit. This is possible but in the case of SWT it is just broken (think about margins, text, scroll behaviour).

The other option is to use electron as it is just plain simple, works even in the web (you can basically make a webapp and repackage that as an electron app)

Or you package a toolkit with your application and avoid native libraries. This happens in the world of Qt for example. Gtk is cross-platform too but not statically linkable.