In the other languages I'm most familiar with (that would be primarily Dutch, French, Spanish), it's not that there is no wordplay, but if somebody starts telling jokes, they're not going to be pun jokes of the "a man walks into a bar" variety. Puns as a genre are much rarer in those languages, or so it seems to me. It's entirely possible that one of the reasons why they're so prominent in English, is the absurdly complicated orthography of English and the countless instances of differently spelled homonyms or near-homonyms. Or it could just be a tradition that someone started and lots of people followed.