That is useful! Wonder why Ctrl-l and alt-d don't work like that?
Alt-d is, AFAIK, equivalent to a menubar shortcut (like Alt-f) that just happens to go to not quite a menu. None of the others close on repeat, so it doesn't either. UX consistency, though maybe the sort that doesn't matter as much as usual.
In Windows' File Explorer, F6 cycles focus between window sub-regions, while Alt+D sends you unconditionally to the address bar independent of where the focus is. So maybe there is a parallel here.