I'm not an expert either. I'm a computer scientist, not a physicist. But the math behind QM -- at least the parts that matter for this discussion -- is pretty straightforward linear algebra. Really, anyone can learn it. So don't take my word for it, look into it and decide for yourself. You can start here:

https://www.amazon.com/Philosophy-Physics-Princeton-Foundati...

https://www.amazon.com/Quantum-Mechanics-Experience-David-Al...

Or, if you don't feel like buying a book:

https://flownet.com/ron/QM.pdf

Or, if you prefer a video:

https://www.youtube.com/watch?v=dEaecUuEqfc

BTW, it may come as a surprise to learn that I am actually not a big proponent of many-worlds despite recognizing that it is in fact a logical consequence of the math. If so, you may find this interesting too:

https://blog.rongarret.info/2009/04/on-shadow-photons-and-re...

and a follow-up written ten years later:

https://blog.rongarret.info/2019/07/the-trouble-with-many-wo...