Why do cross talk jokes always repeat?

Crosstalk is actually based on the structure of historical paragraphs to innovate and expand. No matter whether you write or perform old jokes yourself, you always have to flip three times and four times, and you have to be rigid, with less feeling and more feeling. Every sentence has to be scrutinized, so if you don't have sufficient creative experience, performance experience and improvisation ability, how can you say the previous jokes and integrate them into your own style?