All this talk of multiverses should not assume that the laws of physics apply equally on them all. If they don’t then it is not true for physicists to say as heard on tv, such things as. “we could be having this very conversation/interview on an infinite number of places in an infinite number of universes.” That assumes that multiverses are identical to ours.
However if the speeds of light or sound or gravity are different,the whole of life if it exists anywhere in them, will be very different. An argument for their existence explains that they are in dimensions different from ours. That alone argues against a parallel life does it not?
Whilst I do not have the knowledge to argue the physics too deeply, the need to move into this rarified field is sometimes posited on the grounds that if proven, it will be a major step if not the final link,towards the unified theory. It seems though that if these multiverses exist and are of an unknown number then until they are quantified and the answers to practical difficulties are forthcoming, there are more questions to be answered first on this minuscule planet even before our own universe can be fully understood.
Perhaps even thinking about it puts us too far ahead of ourselves.