No, it’s not “throwing my hands up” and saying “its magic!” It’s making a sound conclusion that there must be a first cause of the universe. If you say that its the multiverse, then there must be a first cause of that. If you say its a tier 2 multiverse then there must be a cause of that. If you say a teir 3 multiverse, then there must be a first cause of that ad infinitum. Eventually there must be some cause that itself has no beginning and therefor no cause of its own.
Although there may be an infinite number of unifying universes, eventually there must be something to cause them all. Although the conclusion that it is God is, admittedly, a non sequiter based on the premises, the conclusion that there is some being or object that itself has no cause is not. Therefore, by pure logic alone, such an entity must exist.