How is Qt within a GNOME or Xfce environment any more "native" than Qt on Windows or Mac?
You have reduced the definition of "native" to merely compatible with X11/Wayland (that's the only common denominator). Well now, Tk, FLTK, Swing, and even Wine are all native.
Both Qt and GTK have facilities for integrating into each other’s desktop environments (see [1]). Sometimes they blend in nicely, sometimes they stand out a bit, but I think it works out pretty okay.
GTK doesn't much care about integrating into a Qt environment and doesn't really implement anything to make that work besides in some cases implementing the same Freedesktop standards. Even for basic things like the look of widgets you need a style that has implementations for GTK - there is no compatibility layer to use Qt styles. Gnomies in general don't care about anything outside their world.
The other way around is a bit better, e.g. there is QGtkStyle but AFAIK it is stuck at GTK2 and does not support using GTK3 styles. Still, behavior between GTK and Qt applications is very noticeably different.
It would be great if there was a shared ABI applications could use but GUI toolkits are too complicated for this to be feasible.
> Both Qt and GTK have facilities for integrating into each other’s desktop environments
Neither Qt nor GTK are desktop environments and Qt certainly isn’t defined by a dominant desktop environment - KDE isn’t even what pays their bills.
You’re still proving my point. The common denominator here (on Linux) is just X11/Wayland. If it works out “pretty okay”, then score one for a cross platform toolkit. Still no idea what über alles “native” means.
Let’s go back to the original comment I responded to… why should I not just continue with the Qt “stupid” “hobbyhorse”
You have reduced the definition of "native" to merely compatible with X11/Wayland (that's the only common denominator). Well now, Tk, FLTK, Swing, and even Wine are all native.