Overboard

Is the argument from Contingecy the most versatile sound argument in favor of the existence of God other than the Kalam? The Jesuit Copleston's statement contra the notorious gooner Bertrand Russel runs as follows:

"We know that there are some beings in the world which do not contain in themselves the reason for their existence. For example, I depend on
the existence of my parents and now on the existence of the air and food and so on. The world is simply the real or imagined totality of individual objects, none of which contain in themselves alone the reason for their existence. There isn't any world distinct from the objects that form it any more than there is a human race apart from its members. Therefore, since objects exist and since no object of experience contains
within itself the reason for its existence, this reason and the totality of objects must have a reason for its existence external to itself. That reason must be an existent being. This being is either itself the reason for its own existence or it is not. If it is, well and good. If it is not then we must proceed further. But if we proceed to infinity then there is no explanation for existence at all. So in order to explain existence we must come to a being which contains within itself the reason for its own existence. That is to say, which cannot not exist." (Afterward he adduces the various attributes, including intellect to set things in motion, having knowledge and power over all things, etc.)