>>40798392 (OP)Because geocentrism is true, and works.
Because geocentrism is simply an exercise in relativity.
Declaring Earth as the inertial frame of reference means it doesnt move, and everyhting else does.
you can do this with any mass.
But some masses as the immovable center make for more complicated models than others.
Doesnt make it wrong, just makes it less useful.
Geocentrism is GREAT for figuring out where things are in relation to the Earth.
It is very bad for figuring out anything else with celestial motion.
Another issue is that geocentrism REQUIRES the Earth to be round for it to work.