AM is used for

This type of radiation can also travel further distances around the Earth than other types of radiation, for reasons we will discuss later. Therefore HF and lower frequency radiation is the best to use for direct long distance communications (when satellites or long cables cannot be used).22 Eki 2003

Higher frequencies provide more bandwidth ; you could send far more data in less time with a VHF antenna than a lower frequency antenna. … And as you increase the frequency, you increase the transmission quality as long as you’re dealing with high-definition signals.28 Oca 2021

The main advantage of high frequency signals is that the signal may be transmitted over very long distances and thus dissipates very less power . The antenna height required for transmission is reduced at higher frequencies.