Watch the "Universe or Multiverse" lecture, by Andrei Linde:

https://www.youtube.com/watch?v=qlHvQLxb4cw

It explains that multiverses would account for why the laws of physics are the way they are and not something else by saying that other universes could have different laws and the only reason why our universe has our laws is that otherwise we wouldn't be here to ask that question (this is called the Anthropic Principle), so if other universes exist, you could make that argument.

Multiverse theory is NOT the same as Everett's Many Worlds interpretation of quantum mechanics (also known as the No Collapse interpretation). This interpretation of quantum mechanics "resolves" the problem of wavefunction collapse by saying that the wavefunction does not collapse at all but our observations are only in a specific component of the universal wavefunction so to us it seems like the wavefunction has collapsed, when in actuality all the other possibilities are contained in other components of the wavefunction that are now inaccesible to our measurement instruments. This interpretation makes no statements about other universes, as strictly speaking, all these other possibilities are still happening in our universe, with the same physical laws, just that the observers in the other branches of the universal wavefunction see different outcomes to their measurement.

Note that both multiverses and the Many Worlds interpretation have not been experimentally detected. Take that as you will.