Likewise. Very sad to see it all start with such promise, and then end up where it is today. If I read your username right, you also helped me get a tutorial published in CVu on GTK+ development around 2005 (which lives on at https://gitlab.com/codelibre/ogcalc). I ceased to maintain it when GTK+ stopped being usable for professional application development (not that, in retrospect, it was ever that great in the first place).

I invested a significant amount of time and effort developing C and C++ applications with GTK+ and Gtkmm. The consideration given to application developers when making repeated incompatible changes, along with a seemingly endless stream of bugs in both, forced me to move to Qt, and I've been using that exclusively for GUI work since the Qt5 timeframe. There's no upgrade path for older Glade project files. Basic widgets have been deprecated and removed. A fairly trivial maintenance cost has instead been imposed upon the entire developer base, in most cases for little or no tangible benefit.

In 2022, where are the "network objects"? GNOME started with a fairly revolutionary and interesting premise of interconnected services using CORBA. CORBA of course died a slow death, but there are modern replacements (not dbus), which could be used to great effect. Over the last 15 years, GNOME seems to have been primarily driven by appearance and usability (by their definition), but the technical underpinnings of the whole thing are fairly shallow and limited compared with what might have been.