I understand the need to use these rhyming slangs during the war, when there was a need to camouflage what you were saying...but why does this continue today.

Why would anyone prefer saying "I Adam and Eve you" instead of "I believe you"?

Look at the paragraph given by belli above. It can be cut in half if you use the real words or have these expressions become the real words?

Does a child who is raised speaking only the cockney tongue know that a barrow is called a barrow in the English speaking world. If you show him a picture of a barrow, does he know it as as a bow and arrow only?

In the dictionary you send us to Belli, there are words that are represented by pretty recent things like Sigourney Weaver and Britney Spears. Would EVERBODY know what a speaker was talking about if they used those two terms?