It is a privacy issue. Apple does not provide access to information about anyone owning Apple products and does not maintain a database about lost/stolen products. The lack of a database is because of the ability of original owners that are registered as purchasers to sell, trade, giveaway products. There is no way for Apple to know who legally, or illegally, may be in possession of devices. The Find My provides device owners to configure their devices to be locked and display information on how to contact them. If the owner fails to do that, there is nothing else that can be done, with the exception of turning devices into law enforcement. If the owner reports a device lost/stolen at a police agency, or someone turns one in, the police can search the serial number through reports of lost/stolen items to see if the owner made a report.