See for example this: https://gitlab.gnome.org/GNOME/mutter/-/issues/4051
Nobody is assigned to fix these.
If nobody is assigned to GNOME bugs it's because developers were more interested in redesigning some app or rewriting some APIs than fixing bugs.
jwz explained it 25 years ago: https://www.jwz.org/doc/cadt.html
Who would be assigning people to the issues? People scratch their own itches or work on what their employer needs them to do.
That's precisely what I meant - there are no employees that are assigned by their employer to ensure GNOME works. That's why the comparison with macOS makes no sense.