and having to pull in hundreds of MBs of dependencies to use just one KDE app, say Gwenview, I'd say that platform agnostic GUI apps are either dead or rare. qBittorrent is a good example of such a rare app that works really well across desktop environments and window managers on Linux.
Yeah, Qt feels better to use compared to GTK but with bugs like these
https://bugreports.qt.io/plugins/servlet/mobile#issue/QTBUG-...
and having to pull in hundreds of MBs of dependencies to use just one KDE app, say Gwenview, I'd say that platform agnostic GUI apps are either dead or rare. qBittorrent is a good example of such a rare app that works really well across desktop environments and window managers on Linux.