1) A root canal is NOT very bad.
2) It does not always require mutiple injections. Depending on the tooth, it might require ONE when starting the treatment and ONE when treatment is completed.
3) The rubber dam is to prevent the leakage of fluid or bacteria into the canal system, which would compromise the success. This is an important step.
4) The " god knows what chemicals " is used to disinfect the canal system of all organic material/bacteria before the canals can be sealed.
5) The tooth is not ruined in order for the crown to be fitted over. It is shaped ever so slightly in order for a crown to be fitted. With modern crowns, the adjustment is minimal.
6) It is not always noisy and stinky. This is only your own idea of what treatment at a dentist would be like.
7) It is not always very expensive. The price differs from molars to anterior teeth. It is often also cheaper than some of the replacement alternatives and the prices is dentist or specialist dependant.
8) It is not always painful. Most of the time it is not.
You can comment on your own experience-which is your right, but clinical advice can only be given by a dentist. Your own experience or what you read, is not always the reality of the situation.