You and I are likely very privileged to be in families with a long lifespan, however, the average lifespan in the US is only about 80 years.
While, I can not say for sure, your ignorance in regards to frequencies may just come from your lack of experience.
I have had 17 years of experience with using zappers and other frequency devices and it is quite possible that they have saved my life more than once.
I have found the following from my experience:
At least some zappers can effectively kill many microbes such as bacteria and protozoa and can do so faster than Antibiotics in at least some cases.
Zappers and frequencies also appear to be able to quickly destroy many virus.
Some zappers and frequency generators can stimulate immune response in some cases.
Where are the medical studies? Since zappers are not medical devices, no medical studies have been done.
There is a study that does show that even the simplest, cheapest zapper can produce positive results with certain health issues. Thiel Study
Additionally, it appears that you never even bothered to read the book "Cure for All Diseases". If you had, you would know that much of it is plain common sense advice on what causes many health issues and how to remove these things such as toxins from your body.