Just a development note, GTK 4.10 has deprecated a ton of stuff. Typically I try to move away from the deprecated stuff to the new components they want you to use, however, similar to what they did towards the end of the GTK3 series, they have deprecated some things with no possible replacements.
The GTK3 widgets that were affected this way were not quite as important, essentially the taskbar API. When using GTK3, it continues using the deprecated GtkStatusIcon API since there is no possible replacement. In GTK4 this functionality is unavailable. This functionality is kind of nice to have, but not necessary. So it kind of stinks, but it isn't the end of the world.
However in GTK4, things have gotten much more serious. They have deprecated the GtkTreeView and GtkComboBox functionality. There is a potential replacement for Tree, using the List and a Tree emulating model, this is similar how the tree widget was implemented on Android and iOS which don't have dedicated tree widgets either.
The big problem is the GtkComboBox, the suggested replacement is GtkDropDown. However GtkDropDown is just a list connected to a button. GtkComboBox does something completely different. It is a List combined with an Entry. There is no replacement for this, so for the time being in GTK4 I will just continue using the GtkComboBox in its deprecated state and hope they give us an actual replacement before GTK5 comes out and a huge number of applications become non-functional due to this missing functionality.
The GTK3 widgets that were affected this way were not quite as important, essentially the taskbar API. When using GTK3, it continues using the deprecated GtkStatusIcon API since there is no possible replacement. In GTK4 this functionality is unavailable. This functionality is kind of nice to have, but not necessary. So it kind of stinks, but it isn't the end of the world.
However in GTK4, things have gotten much more serious. They have deprecated the GtkTreeView and GtkComboBox functionality. There is a potential replacement for Tree, using the List and a Tree emulating model, this is similar how the tree widget was implemented on Android and iOS which don't have dedicated tree widgets either.
The big problem is the GtkComboBox, the suggested replacement is GtkDropDown. However GtkDropDown is just a list connected to a button. GtkComboBox does something completely different. It is a List combined with an Entry. There is no replacement for this, so for the time being in GTK4 I will just continue using the GtkComboBox in its deprecated state and hope they give us an actual replacement before GTK5 comes out and a huge number of applications become non-functional due to this missing functionality.