I would say that brag tags as I call them can be very useful if you are young woman since you lessen the chance that someone will question you (yes some airport workers are that sexist, I have seen it myself) if you are in the correct line or not when checking in or boarding. You can get better treatment if you flaunt one of these tags on your fancy bag. Also if you fly economy with one of these on a nice expensive bag and also dress nicely, the cabin crew who notice it might make the assumption you are just flying economy because it was a last minute booking but that you normally fly business class. If they make that assumption there is a chance you will be better treated with regards to service on board.

So yes there is some use for these in certain circumstances. But generally they are just for show or bragging rights!