https://bugzilla.mozilla.org/show_bug.cgi?id=1267863
https://bugzilla.mozilla.org/show_bug.cgi?id=635044
I predict that someone will get fed up enough to revive the Firefox Qt port, since Qt doesn't break as much between releases, and it doesn't conflict with Mozilla's plans to drop GTK2 support. The memory overhead of Qt is absorbed within a modern browser's memory needs.
GTK3 drags in way too much of gnome for comfort, but I don't want to drop all GTK3 apps, so I have to put up with it.
When GTK3 and even Qt5 go user-unfriendly and dev-unfriendly ways, it's no wonder there's many immediate mode ui library projects that are popular or actively developed Haskell FLTK bindings.
https://www.freshports.org/x11-toolkits/gtk30 It's "lean" by default, you can't even make it "not lean".
They're big, but I wouldn't call them "user-unfriendly and dev-unfriendly". QML/QtQuick is the best GUI development thing ever.
P.S. I was building Firefox from ports for a while, just to get GTK3 support earlier than they turned it on by default :-P
For WM, I use i3. If you don't mind tiled, I'd highly reccomend it. It's great, the docs are great, and the config file is easy to understand, so after the base setup, you don't have to worry about it.
XFCE, TWM and sawfish are pretty cool, if you're not into tiled.
Yes, Tk just works for gui and is underappreciated.
wx's default backend is gtk (2 or 3) and they have an experimental Qt5 backend now, which is unsurprising given GTK3's state. So wx doesn't help, unless you can make the Qt backend work (Qt5 is so modular that it's often a pain).
Gtk3 may be faster in theory due to GPU acceleration as a possibility, but when Gtk 3.20 for a split second shows a black rectangle for each new dialog while it's opening, I have a hard time taking their gpu acceleration argument seriously.
I tried building Firefox 48 with gtk2, but it crashed in the file dialog, while the gtk3 build is slower and introduces gui regressions (yes, I've reported the gtk3 bugs). Right now I cannot move past Firefox ESR with gtk2, and I hope I can still use Firefox next year.
What I'm saying is that GNOME3's stack (especially Gtk3) doesn't seem to work outside GNOME3 as compatibly as Gtk2 does, and it may be what's intended, if past communication from the GNOME dev team is any indication.