The reason is actually pretty simple, it's easier to work at higher voltage and lower current and it's also easier to filter HF than LF. The large coils and caps required to filter 100Hz or 120Hz (full wave rectified) power are more expensive, and the components required to channel higher currents are more expensive too. All the same reasons we distribute power at kilovolt potential and then transform it down to household current levels.

None of this really suggests which type is better, because there is no better type. Both can be made to perform very well. It's all the "same stuff" really, just "smooshed" into different forms.