[Houshalter]

You are making my argument for me. The hypothesis "unicorns don't exist" has zero proof. You can never ever prove that unicorns don't exist. Therefore, the statement "unicorns don't exist" is just wild speculation and outside the realm of science. Therefore, until someone shows proof we will assume that unicorns do exist.

The idea that our universe is the only universe is just as crazy to me as saying unicorns exist. The laws of physics are incredibly arbitrary, and the probability of a random set of laws of physics supporting intelligent life is ridiculously small.

More formally, via Solomonoff induction, the hypothesis of multiple universes should be more likely by several orders of magnitude, since it can necessarily be expressed with fewer bits of complexity. E.g. "all computable programs" vs "one specific program", or "all possible laws of physics", vs "one very specific set of laws of physics."