I have yet to find a cross-platform UI framework that really feels native on Gnome. The reality is that there is no shortcut for native UI on all platforms, you have to use the “official” framework (e.g. GTK for Gnome). In my opinion the only softwares that should use a custom framework are professional grade apps where custom workflows can’t fit the native UI (e.g. Blender). Despite all the noise about native cross-platform frameworks, it’s absolutely not fooling anyone, we can spot this immediately on any platform.

This correct. What's actually needed is a modernized wxWidgets. The goal of the GUI framework should be to find an architecture that is maximally compatible with the native Windows, GTK, QT, Mac OS UI frameworks/libraries plus a simple way to accommodate minor platform differences.