Conservation of energy requires an absolute reference, therefore a center of the universe.

The assumption of relative reference; no preferred reference, can violate energy conservation. For example, say we have two rockets in space at relative velocity V. One rocket has mass M and the other has mass 2M. With relative motion, each can assume they are moving, or each can assume they are stationary and the other is moving.

Although this will work for velocity, relative reference will not work properly for kinetic energy. If rocket M is moving, the system kinetic energy is 1/2MV2. On the other hand, if rocket 2M was moving system kinetic energy is MV2. These are not the same amount of energy. Since energy conservation is a law, reference needs to be absolute to get the proper energy.

For example, say we assume rocket M is in motion. However, in reality, rocket 2M burnt the fuel and therefore has the real kinetic energy. Since our reference assumption will short the universe energy, 1/2MV2 of kinetic energy is subjectively destroyed. This implies we now will have 1/2MV2 of invisible energy in the universe, that we may not notice, right away, which will not be part of universe assumptions. But eventually, this hidden energy, that would have been obvious had we chosen our reference wisely, begins to show up as inconsistencies in phenomena relative our reference. We need to add new things we originally did not need.

An analogous example is say we live up on a plateau, where there is a beautiful lake. Out of convenience we call the lake on the plateau the zero reference, since the prime lake front property is where our tools are, and where all the big wigs live. Since the plateau has a potential relative to sea level, which is the real zero reference for the water, we end up with hidden energy; hidden potential energy in the water.

One day, careful measurements reveal the lake level is dropping. We rule out evaporation and lateral diffusion. Since the lake is the ground state, the potential can't be in the water. Rather it has to be in the guise of new form of energy, called plaid energy, which is causing the water to go through a space-time portal into another dimension. That theory brings us closer to the actual energy balance, while maintaining relative reference. But if brings something to the table we can't see in the lab.

In our universe, the speed of light is the ground state. From that reference the center of the universe is always the same, since the inertial universe always remains a point-instant in the ground state.