First, they are called "sights", not sites. Second, the bullet travels the same 'straight' way (actually a slight curvature, because of gravity), with the pistol tilted or upright. It should have been "to make sure the bullet travels toward the target".
It is true that the 2 sights and target take too long to line up for fast action, and a point-and-shoot approach is needed. However, a nice laser sight will paint a dot on the target very quickly, and allow quick shooting from the hip.
” First, they are called “sights”, not sites.”