A satellite in a geostationary orbit appears stationary, always at the same point in the sky, to observers on the surface of the Earth.
[1] The added velocity reduces the fuel needed to launch spacecraft to orbit.
Westward launches, in fact, are especially difficult from the Equator because of the need to counteract the extra rotational speed.
The maneuver to reach the 5° inclination of the Moon's orbit from the 28° N latitude of Cape Canaveral was originally estimated to reduce the payload capacity of the Apollo Program's Saturn V rocket by as much as 80%.
However, a non-inclined orbit need not be referenced only to an equatorial reference plane.