My guess would be that it has something to do with corporate phone systems. In some cases they want all incoming calls to the front desk or 800 number regardles

My guess would be that it has something to do with corporate phone systems. In some cases they want all incoming calls to the front desk or 800 number regardless of the outgoing number - and it’s not all that uncommon for each desk in an office to have an actual individual number instead of an extension. So that outgoing calls all have the front desk as caller ID, but individual employees can choose to give out their direct number to vendors or important clients or whoever. Not that that justifies allowing the system to be abused like this.