All these theories and speculations interest me as much as anyone, however there is really only one answer to the question that is unassailable.
What allows any and all of these possibilities to exist are THE LAWS OF PHYSICS. That is the one prerequisite for everything else, real or imagined.
You may say that there is no evidence that the laws of physics are static. While true, this simply means that the “laws” include one or more randomized variables (or randomizing functions.)
You might argue that the laws of physics are no different than God. While I believe that this is what Einstein meant when he referred to “God” or “the Old Man”, the laws of physics don’t imply any supernatural “super-nature”. By definition, nothing can be more natural than the laws of physics.
YMMV.
Peace