[Brian Swartz]

I don't think it's BS. I think it's unknowable/unprovable at this point. We aren't even certain our own universe has the shape we think it does, or whether it has boundaries. It's kind of like medieval Europeans thinking Earth was smaller than it is and having no idea the New World existed. Talk to them about other planets and they'd be dumbfounded.

If you look at how quantam mechanics works though for example, to me that's a far stranger reality than the idea of a multiverse. We're nowhere close to having a 'theory of everything' that explains how the physics of the small and the physics of the large fit together. We don't fully understand gravity even - we know what it does, but not why/how. There's a lot of unknowns, to the point where I think it's way too early in our scientific understanding to rule out multiverses. The way black holes function, to the degree we understand it, is absolutely insane even to physicists.