You can have an infinite number of identical universes thus never getting to every possibility. Between 1 and 2, there's an infinite amount of numbers without ever reaching 3. Infinite universes doesn't mean infinite possibilities. Not to mention, there's multiple multiverses. By that logic, the main DC Comics universe is in the Marvel Multiverse because there's infinite universes (as is The Big Bang Theory, Back to the Future, etc.), except that's not true. It exists in the separate place that also constitutes infinity.