Nothing in nature is infinite. Absolutely nothing. Not the grains of sand on a beach, the stars in night sky, the atoms in the universe, the speed of anything, the power or temperature of anything. Everything has a hard number. We just might not be able to calculate what that exact number is. Infinity is a man-made concept. It is not a real universe thing.
The universe was not once an infinitely dense singularity. How could it be? It doesn't have infinite mass now. It wasn't infinitely hot ... there isn't infinite power now and you can't lose a bit of power and say well now it has gone from the hard number infinity down to a smaller number which is not infinite. Infinity - 1 is still infinity, it isn't compatible with real world numbering. Whenever I hear a scientist use the word infinity, they are invoking God. When you need infinite universes to make your theory work based on the one observable universe we can see, its a thought experiment, a way to discount the notion of God, but ultimately just replacing it with another theory of god ... infinity.
There is only one infinity. Infinity is the scientific word for God. God is the alpha and the omega, the beginning and the end, all things and everything. The mechanism by which all things are created. Only God is infinite, infinity is His name, and like I said, infinity is a man made concept. It isn't a way to explain God, just another word for it that people can wrap their heads around. Scientists are playing word games, they haven't any explanation whatsoever.