One of the main problems with monotheism is that at once the monotheist has to prove the existence of his god, both to himself as well as to others. Further than that, he then also has to prove that his god is the only one. And, beyond that, he has to prove his entire religion to others.
The polytheist does not have that issue, for we have no need to prove anything to anyone else since we do not proselytize. We do not even care if others believe our deities are real or not. And the deities themselves have no need to prove their own existence to anyone.
This is, in fact, the inherent weakness of monotheistic systems – the need to prove. It is an inherent fault of monotheism that it has to constantly prove itself.
Again, the polytheist has nothing to prove and we don’t proselytize. The only detriment that I see in this is that it also does not allow Pagans, as a religious entity, to be fully recognized as legitimate by those of other mainstream religions, or by society in general. And this prevents us from advancing toward becoming fully recognized, for example, by the military, so that a need for Pagan chaplains can be seen. I am not suggesting that Pagans should all be able to come together and unite as one; but we lack any sort of cohesion that might make some form of recognition by others possible. As long as this is the case, we will never see Pagan chaplains in the military, Pagan libraries and schools, or Pagan places of worship in various areas as we see with Christianity. There is no way to compete with a religion like Christianity if we cannot, at a minimum, form some sort of cohesiveness that would allow us to be seen as legitimate by the world at large. This is simply a fact, and nothing will change this within the next generation or two other than a determination to make it happen, which we seem to lack overall as a movement.