The multiverse exists. I know this as I have experienced it and if you are a parent, you have likely experienced it too. I do not have statistical or scientific evidence of this, but I do have anecdotal evidence of its existence.
I was at a children's birthday party and was introduced to one of my wife's friend's husband. We shook hands and introduced ourselves.
"Hi, my name is Alexander. Nice to meet you," I said.
"Hi, my name is Andy (my guess is it was Andy as I actually don't remember). Nice to meet you," he replied.
We shook hands and then I blinked my eyes. When my eyes opened again, I had jumped between multiverses. It was obvious that I had just traveled between multiverses because I was now standing 50 feet away, putting a helmet on one of my kids. I turned around and that Andy fellow was just standing there, with a drink in hand, staring out into the field. How in the world did I go from there to here? Did I even meet this Andy person? Was I now in a multiverse where we had never shake hands?
Either I was able to travel instantaneously from one spot to another in the same universe or I was able to jump from one multiverse to another. It's obvious which is more plausible.