You have offered a second “straw man” argument.
This has NOTHING to do with inertia.
This has EVERYTHING to do with the change in the angle that a portion of the earth would exhibit if it were to rotate. No jumping. No floating. No inertia. Just change in the angle over time.
Okay, I’ll give up on the rotational inertia argument. If the earth does not rotate on its axis, how then do you do you answer a more expanded version of edh’s question:
Why does a fixed spot on earth experience a pattern of (approximately) 12 hours of sunlight, then 12 hours of no sunlight?