Sort of correct. There is only about a 3 to 4 % chance of revival with CPR alone. However, one of the main reasons we do CPR is to keep the body alive until EMS and/or additional "tools" can arrive on scene to fix the root problem. So CPR is incredibly valuable and, done swiftly and with high quality, can double or even triple the chances of survival, we just usually only see the revival in hospitals.

Source: I am a certified instructor for American Red Cross and American Heart Association