Why don't they count? Already employed people are recruited by Apple, I get spammed by Apple recruiters, I know a dozen of people who had been poached by Apple from various companies. Apple does hire people who are already employed, they pay quite a bit more so many employed people are looking if not for increased prestige then for increased TC.
>Imagine someone leaves whatever company they are at to take the role at Apple. Now the company the employee left has an opening that can’t be filled.
I am not sure I follow, this is obviously false on its face. Why exactly can not it be filled?