If the developers have done things in scale, trees, houses etc ... using the correct formula Velocity = Space / Time, we should have the same perception as reality but as you say this does not happen and I believe you, in fact it does not happen for two reasons .
The scenario does not have the same details as in the real world and therefore the low altitude flight seems slower because due to the fewest static points of visual reference.
The fov. The fov plays a huge part in the perception of speed, this is a fact.
So unless the scenario is rich in details, and unless you use a VR viewer with + 200 ° of fov, it is impossible to have the same perception of the real world.