For users there are two perceptual disadvantages of a one button to press system: (a) there is no need to go through the whole list and (b) the information cannot always be presented in the proximity of the controls.
Modiriso o, o itsege ka dintlha tse pedi, e leng, (a) Modiriso o o ikemetseng ka boone, ke go re ga o a ikaega ka mediriso e mengwe le (b) ka gale o nna polelwanakutu.