I’m asking because this could be further evidence that a universe cannot come into being on its own. If a universe can come into being on its own, that means there are infinitely many universes that could come into being, which means there are infinitely many universes that could “collide” with our universe. Since no universe has “collided” with our universe, universes do not come into being on their own.

Who told you that none has collided? What would such a collision even mean? And why would there have to be a collision? A very weak argument.