Why is the "allocate access" button not visible for certain company level users on the User Org Unit Permissions screen?

Why is the "allocate access" button not visible for certain company level users on the User Org Unit Permissions screen?

Alert
This feature is available on Premier and Master editions

Navigate > Config > Security > Security > User Org Unit Permissions

If the "allow access to all employees" toggle is switched on for a company level user, the "allocate access" button will be hidden. Once the toggle is switched off, the "allocate access" button will appear.