Gravity is not a constant. At various places around the world there are slight measurable differences between what is measured. Not just Mt Everest.
I have performed these experiments in a university environment, with a couple of professors and a multitude of fellow students. Maybe the professors were in on the conspiracy of course.
We tend to use the 9.8 m/s as a generalization. So if we are to assume we are on an accelerating disc, then the landscape itself beneath our feet would be constantly rising and/or falling to such a degree that valleys and mountains would be forming before our very eyes in order to create these variances. Would this not be so?
Of course the other explanation according to RE is the further away from the surface you are the lower the gravity. According to the physics of velocity for the FE that wouldn't make a difference.