When people speak in the vernacular using slang, it broadens the English language by adding more words. Language isn’t static, and a language such as English is a collection and reinvention of the words of many other languages such as Latin and Greek, as well as the romance languages of Europe.
As civilizations grow, change, and expand, so do the words in the language. Slang phrases such as “23 skidoo” might’ve been what the hep cat of 1925 was saying to his flapper girlfriend; but, as time passes, many slang phrases tend to fall by the wayside.