Many Worlds Interpretation (MWI) is favored by EY as having a shorter message than others.

However, the short-message version of MWI does not include a theory as to how my particular stream of consciousness winds up in one branch or another. So Copenhagen (wave function collapse) is a theory of what I will experience, MWI is not.

Further, I have always thought MWI motivated by the ideas behind Einstein's "God does not play dice with the universe." That is, a non-deterministic theory is no theory at all. And then, MWI, would be a theory without wave function collapse, so a theory with no randomness. But of course, it is NOT a theory of what a particular observer will experience. To go from MWI to a theory of what I will experience, it seems I still need to have a random function. I suspect some will answer, "no, there is one of you in every branch so MWI predicts you will experience it all, but in separate non-interacting branches. No randomness." To which I would reply, we still need a theory that accounts for my subjective experiences, how did this me, the one I actually wound up as, "choose" between the various branches. To me it would seem essentially theological to say that because some me I can't see, hear or interact with in any way experience all the other possibilities that there is no randomness in the universe. It sure seems random that I wound up experiencing this particular version, in the absence of a non-random theory of that.

Please take this as an invitation to educate me or discuss the conclusions I reach. I am interested in sorting out just what MWI really gains you when leaving Copenhagen, and as competing theories of my own personal experience, they both seem to have, essentially, a random choosing event at their core: one calls it wave function collapse, the other one tries not to talk about it.