The Multiverse is fiction and it is actually easy to show.

Write your name on an envelope, your address, city, country, planet Earth, Solar System, Milky Way, and Universe. Then hand it to a postal person.

The postal person will deliver the envelope to the person on the envelope (you), but also declares that all items except one gave directions.

The word Universe on the envelope did not deliver any direction. It is a real word, but it is a non-functional word.

If someone does not like that, then they can add Multiverse to the list.

Low and behold, the non-functional Universe became functional all of a sudden. It is not just any universe in which to deliver the envelope. Rather, it is OUR universe.

In truth, the postal person still says there is a non-functional word on the list, but this time it is Multiverse.

So, the can got kicked down the road. The non-functionality did not disappear, it just got pushed out of the way.

Conclusion: The word Universe is a word. It is not a unit. There are no details pointed out in the word Universe; it has a collective and all-inclusive nature. It even includes opposites that cannot be made one, such as finite matter and infinite space.

Sorry, physicists that like the idea of the Multiverse, because it is a brain fart. If this were something from our ordinary reality, we'd all say: Get a Life!