The main thing that radiofrequency does is to tighten skin. This happens via two mechanisms: RF stimulates existing collagen contraction; RF stimulates new collagen and elastin synthesis. In fact radiofrequency is the best way to achieve both collagen contraction and production. Any other technique is simply not effective enough, unsafe or both.
When it comes to skin tightening / toning / lifting, radiofrequency is the only game in town.