GTK 4 was released last month and will probably become widely available over the next year or two. There's no rush to port to GTK 4 given the huge number of important issues in our issue tracker, but it would be nice to at least replace the deprecated GTK 3 parts that we can right now.

At least one low-hanging fruit I know of is the gtk_pointer_grab deprecation warning (or something along those lines) that's been around for over a year.

This issue is very low priority.