>>14412961Not him, but I'd say a multiverse is like God in that neither are currently observed.
That said there can be a pretty substantial difference between two different unobserved hypotheticals in terms of how convoluted the idea is or how much support it has outside of direct observational evidence.
The standard model of cosmology (Lambda-CDM) assumes the generalized Copernican principle that we aren't special or in a privileged / central location as far as the rest of reality goes. So our observable universe not being the only thing in existence and not being anything particularly unique compared to all other possible universes would follow from that standard model's assumed Copernican principle i.e. The premise isn't just random nonsense and is expected to some extent even if we don't see it or have a way to see it.
And.arguably it doesn't make much sense to assume what we happen to be able to see is coincidentally identical with the exact borders of reality itself. It's not clear reality having borders beyond which nothing exists is even a coherent idea let alone the way reality actually works.
