The theory of an infinite number of universes is the alternative to the theory of a created universe. Both explain the statistical impossibility of our universe being so fundamentally tuned to support the evolution of sentient life that it could arise by chance. Science itself dictates there has to be either an infinite number of chances, or an outside constraint on the fundamental nature of the laws of the universe.
It is also true that science has nothing whatever to contribute to choosing which of those theories to believe. No experiment can be done for either one. Therefore, believing either one is a leap of faith. Choose whether you believe the universe has a purpose and what you do in your life matters, or that we are meaningless.