This question already has an answer here:
If the universe started out isotropic and homogenous and of all fundamental particles then how could there now be any concentration of energy anywhere? If you say that nothing is really homogenous because of the grainy quantum nature then what about when it was all compressed in one Planck volume? Is the universe allowed to do this because it emerged hot, essentially getting all its heat from nowhere? All that heat dissipated into the CBR. But nonetheless some things are hotter than others and we can do meaningful work now while in the beginning everything was the same state, temperature and particles.