Do you know what happens with quantum entanglement, or how quantum encryption works- or are you familiar with the Born interpretation of the Schrodinger equation.
Multiverse is a decent theoretical explanation for why matter demonstrates waveform superposition distributions and interference/coupling patterns.
Disclaimer: I'm an aerospace engineer that crossed trained as a lawyer. So you seem about to get into the weeds past where I'm competent to trade blows with you.
That being said...
I am familiar with quantum entanglement and quantum encryption. I have clients whose technology relies on quantum entanglement to create quasi-particles (like polaritons) that are then used in various applications ranging from quantum encryption and quantum computing to more exotic uses. To assist their work, I have to half-way understand this stuff, although I was warned that only a dozen people on the planet actually "understand."
I'm obviously familiar with the Schrodinger's equation, but I had to look up the Born interpretation. (Always good to learn something new).
As for a theoretical explanation for why matter demonstrates waveform superposition distributions, etc., I'm aware that this is one of the postulated explanation for not really explicable collapse of wave functions.
This explanation has always dissatisfied me. The uncertainty principle and the measurement problem are uncomfortable, but it seems un-parsimonious to postulate an infinite set of universes with all of their associated mass and energy just to cover up the fact that we can't know where an electron is and where it's going at the same time.
My understanding is that while the Schrodinger equation is linear, wave collapse is not and so you just go round and round and round arguing about the probability function relating to the branch where we exist and the probability function of the particle to be observed.
Worse, the attempts to use this concept to come up with a measurable observation (typically, trying to show the cosmological constant is a result of multiple universes) have failed.
Smarter people than me, such as Sabine Hossenfelder, have explained why the multiverse/multiple worlds hypothesis is not science.
Bringing this back around to my original post, the metaphysical impact that the multiverse/many worlds idea was intended to avoid is simply the fact of a cosmic beginning.