In our previous example, a satellitle traveling east to west on the equator travels at their velocity plus the earth's rotational speed, whereas a satellite traveling west to east travels it's velocity minus the earth rotational speed.
The two main problems with that statement are that:-
1) Velocity is a relative value. What you say might be true reference the Earths surface, but that is not the only way that velocity is measured.
2) Velocity is a vector quantity, meaning it is expressed with magnitude and direction. Stating one velocity is less than another is meaningless. You are talking about speed, which is a scalar quantity.
For extreme p, one effect of the Earths rota ion is that it is NOT spherical- it is an oblate spheroid significantly flattened at the poles as a result of its rotation when it was young and molten. This means that many route are shorter using polar routes.
Another effect of the Earths rotation is Coriolis force, which has a negligible effect on aircraft in flight, but is the route cause of weather systems, which are VERY relevant to aircraft operations.