Hizzie hit on it. Staging is context dependent.
Here’s a context where I most frequently find myself staging:
25+ yard shots with a J-frame.
I think of staging like I do cocking the hammer on a DA revolver. It’s largely irrelevant, but may be useful. It is, however, an advanced trigger control technique. And it takes a lot of dryfire and livefire to do it reliably. It’s not something to bother with, until you can call your shots reliably shooting DA.