Through observation, we cannot determine as a matter of fact whether the heliocentric or geocentric model is ontologically true.
From the point of view of an observer on Earth, it would appear as if the Sun is orbiting around Earth. Similarly, from the point of view of an observer on the Sun, it would appear as if Earth is orbiting around the Sun.
At this point, one might be tempted to launch a recording device into space to observe which object is orbiting around which from a third-person view.
If we know as a matter of fact that the device is absolutely stationary, we would finally be able to observe which object is orbiting around which. But how can we determine whether this device is moving or not by observation? As you can see, we recursively fall into the same problem ad infinitum.
While one model may be mathematically simpler (an epistemic preference), simplicity itself does not dictate ontological reality.
Here is an interactive visual illustration of the argument: Heliocentric vs. Geocentric Simulator