I recall some famous comedian saying on The Johnny Carson Show that if he tells a joke on TV then that's it gone however Frank Sinatra however, can sing "My Way" a zillion times and each time the audience laps it up.
In the same vein, comedy songs have a short shelf life while most other songs, especially the ones with a bit of quality, can last forever. Comedy songs about topical subjects of the day become 'yesterday's papers' very quickly.