Lucy and Matthew are the only 2 'celebs' with something close to rock solid careers in the real world. Barring the Wright Show being axed or Chastity Dingle being crushed by a falling pub, both have got long-term, well paid jobs to go back to post-Jungle.
As for the others - it's a lottery and a gamble. Some will sink back into obscurity, some will carry on with their so-so careers on other reality TV shows, and some will milk their 15 minutes of increased fame by pursuing higher-profile TV roles, which may or may not come to anything in the longer term.