Are we co-creators or just experiencing our own perception of reality?

This question depends on the existence of the multiverse, but I am also curious about how this would work if the multiverse is not real and our universe is, in fact, the only one in existence.

Also, forgive me if you think I sound dumb for mentioning supernatural phenomena (with the premise that they are not simply hallucinations.)

People often use the wave function collapse theory to explain how different realities can be manifested by projecting certain frequencies. I’ve also seen similar explanations suggesting that poltergeist phenomena (or pk manifestations) come from the accumulated energy of someone depressed for prolonged periods.

This is all well and good, but regardless of how people apply the wave function collapse theory and the concept of frequencies, and whether you agree or not, I still want you to consider my following question.

Would we, therefore, be co-creators of reality with our fellow humans, or would our perception override everyone else’s perception in determining our own reality and the frequency or reality we choose to tune into, from a physics perspective?

Would this imply that everything about my current reality is my own doing (assuming there are no co-creators)? And if not, does this mean that there are absolutely no other universes or realities outside of our current one? If other realities do exist, would we even be able to switch our reality simply by willing it through perception?

I’m really hoping for a logical (albeit extremely theoretical) answer to this, because even if I were to believe in spirits, I would assume there is some scientific reason behind their existence. It’s ok if it’s purely guesswork as I know my premise regarding the multiverse itself is up for debate.

Thank you so much!