I think you are all missing the purpose of Mode S.
Last Sunday I was flying north towards MAY, on my way to KB, squawking 0012, listening out on LGW Director.
The controller says "Hello Timothy, would you like to go direct Biggin?"
What a narrow life you lot lead!
But actually my mentioning Mode S was only illustrative of a possible issue where one grouping may not see eye to eye with another.