Years ago, the root canal treatment was done with traditional dental equipment which might have caused pain. With the introduction of modern technology, things have become really different. The pain that you experience is mainly caused by tooth problems and decays. The roots of the teeth get infected and that can cause your gums to swell and you might experience a lot of discomfort and pain. It is important to remember that root canal treatment is done by endodontists who are experts in pain management.
Also, there is a myth that tooth extraction is better than a root canal. This is not the case, it mainly depends on the problems that you are facing. However, it is always suggested that you should try to retain your natural tooth if that is possible. Root canal treatment has a high success rate and it can last you for a lifetime.