I also got intrigued about the same when I read about it months ago @sauravrungta. According to what I learned, there are infinite worlds which we live at different points in time and all of that coexist, which means whenever we interact with anyone, we are actually interacting with ourselves and not anyone else.
Just imagine how empathetic the world would be towards others if this happens to be accurate, and people start believing in it. There would be no issues in the world and just peace.
Also, to add to what you have mentioned here, I would want you to read a short story, The Egg by Andy Weir. You will be able to find it on Google. It's a great read. You should give it a shot.
I can paste the link here if you want.
The many-worlds interpretation doesn't say that when we interact with anyone we actually interact with ourselves. It simply says that all the permutations and combinations of our lives (infinite possibilities) all exist in the multiverse at the same time.
Everything being one, is another concept which says that the entire existence is simply one energy and we stem from that energy. And yes, this is a realisation that would change everyone for the better.
Will surely give that a read. Thanks for sharing!