Honestly, there is no real point at all; not on hand luggage, and not really on checked hold luggage either...
I do use them on both, but it's only because I'm relatively young and often look pretty casual when I travel and/or I'm travelling with wife, baby and all the kit....and to be honest I just got bored of quite frequently having BA staff "check" we were in the right place when queuing for First check-in / fast track / Gold lounge...not in a mean way, but clearly always anticipating we had somehow got it wrong because we didn't look like the 'typical' GCH group...(if there is such a thing).
So I do use them for that, and it does seem to cut down the number of pointless interactions on these things as staff can see for themselves that we're fine where we are...
I take them off generally if I'm travelling for work, in a suit or whatever when I fit the 'profile' somewhat more obviously.
I guess that's really just a form of DYKWIA, but it's for a just cause...