From astrophysicist Ethan Siegel at Forbes:
The multiverse is inevitable and we’re living in it
What is the Multiverse, then? It may go well beyond physics, and be the first physically motivated “metaphysics” we’ve ever encountered. For the first time, we’re understanding the limits of what our Universe can teach us. There is information we need, but that we’ll never obtain, in order to elevate this into the realm of testable science. Until then, we can predict, but neither verify nor refute, the fact that our Universe is just one small part of a far grander realm: the Multiverse. More.
In other words, the multiverse is to be accepted as science, even though it may never be testable, thus never falsifiable. It is admitted as “metaphysics,” but that’s okay too.
Now that consciousness is an illusion, so is reason.
And naturalist metaphysics is now officially science. How far we have come from Einstein and Planck…
See also: Question for multiverse theorists: To what can science appeal, if not evidence?
and
The multiverse is science’s assisted suicide