Why are checked bags not being scanned all the time?

Some days ago I came back from a trip. My checked bag did not. The airline does not know where it is. I can just hope it turns up.

To me that is a horrible system. If bags were scanned each time it entered a plane, a baggage belt, an airport, was inspected by a certain person and so on... it would be easier to locate it. Probably also easier to make certain people responsible for luggage not being handled correctly. Are there plans to do this?

I'm thinking they could either just scan the bar codes that are currently being used or add RFID tags if necessary to automate the scanning.