The term Metaverse is sometimes used to describe a collection of all possible universes. We'll expand this term to include our interpretation of QFT, marrying space-time with many-universe interpretation of Quantum Mechanics. A relativistic Metaverse is a collection of events. Unlike in Special Relativity, these events are not points in the traditional four-dimensional space-time. They are points in an infinite-dimensional continuum, which encompasses all possible histories (paths, Feynman diagrams). The Metaverse does have directions corresponding to space and time, but it also has infinitely many dimensions in the direction of neighboring universes. You may think of a universe as one of many possible four-dimensional cross-sections of the Metaverse, slices that can be parameterized by four space-time coordinates. But there is really nothing that forces us to consider cross-sections and identify them with some traditional universes. For our purposes we'll just imagine that each event has a well-defined neighborhood that extends in the direction of all possible dimensions of the Metaverse. This neighborhood encompasses a chunk of space and time, but it also contains events that take place in "parallel universes" (see Fig 7).
What QFT calculates is the amplitudes of transitions between points in the Metaverse. It does it by summing (integrating) all possible contributions from all possible histories. Perturbation theory is just a method of slicing the Metaverse in order to calculate these contributions.
Let's go back to our example of an electron going from point A to point B (see Fig. 6). There is a slice of the Metaverse in which the electron simply goes from A to B. But when we start deforming this slice, so that it bulges towards other universes, we'll get contributions corresponding to virtual particles being created and absorbed. Feynman diagrams provide a neat way to organize these slices into topologically distinct categories.
Indeed, in this picture, perturbation theory is a mathematical device. It's a trick that lets us evaluate, to arbitrary precision, an infinite-dimensional integral over the Metaverse. At this point the physicists don't know how to evaluate such integrals outside of perturbation theory, but they hope this will be possible in the future.
Taking the idea of the Metaverse to its full extent, we have to agree not only that all past and future events exist (by the argument given in the discussion of Special Relativity), but also that all possible versions of all events exist. In a sense, this is the opposite of predestination: No single future is preordained; instead all possible futures (and pasts) are fixed once and for all in the fabric of the Metaverse. The laws of physics describe nothing else but the geometry of the Metaverse. Notice also that we have to allow for the existence of all these bizarre universes with virtual particles, which we can never observe directly.
This way of looking at QFT has one tremendous advantage—conceptual simplicity. The question is: how do we reconcile this picture with our experiences? We can't even approach this problem without some understanding of the conscious mind. And what's the best way of studying the mind if not by performing thought experiments?