Not necessarily - pavucontrol switched to GTK4, and there are a lot of other applications that I use that are on it as well.
If XFCE stays on X11, I wouldn’t be able to run any application that updates to GTK5 (except through some hack like running Weston nested in X, which I used to do when I used Waydroid).
It’s true that there are some apps not directly associated with any DE that have moved to GTK4. If GTK5 actually was likely to come out any time soon you might have to worry about finding alternatives when they switch to GTK5. That being said though, GTK3 had been out for over 9 years before GTK4 came along, there were 4 years between the “last” version of GTK3 and GTK 4.0.0, they’re still in the “oh, this is what we’ll probably do when we release GTK5” phase of development, XFCE has already made a bunch of progress porting everything over to Wayland, and DE agnostic apps are less likely to switch over right away if mid-size DEs like XFCE and Cinnamon still don’t have good Wayland support. I wouldn’t stress out about it too much.
XFCE is still using GTK 3, why would they care what Gnome does with GTK 5? Nobody but Gnome is even using GTK 4.
Not necessarily - pavucontrol switched to GTK4, and there are a lot of other applications that I use that are on it as well. If XFCE stays on X11, I wouldn’t be able to run any application that updates to GTK5 (except through some hack like running Weston nested in X, which I used to do when I used Waydroid).
It’s true that there are some apps not directly associated with any DE that have moved to GTK4. If GTK5 actually was likely to come out any time soon you might have to worry about finding alternatives when they switch to GTK5. That being said though, GTK3 had been out for over 9 years before GTK4 came along, there were 4 years between the “last” version of GTK3 and GTK 4.0.0, they’re still in the “oh, this is what we’ll probably do when we release GTK5” phase of development, XFCE has already made a bunch of progress porting everything over to Wayland, and DE agnostic apps are less likely to switch over right away if mid-size DEs like XFCE and Cinnamon still don’t have good Wayland support. I wouldn’t stress out about it too much.