To give you an understanding of the difference between frequencies. The smallest size sign wave in Shortwave radio is 10m or little more than 30 feet. A 5GHz wave in a modern Wi-Fi router is about 2 1/2" high. That shorter wavelength means that the energy is lightly to pass through you rather than over you as a longer wave such as Shortwave would. Longer wavelengths are better than shorter wave lengths.
The comparison made in the article is a complete joke.