What physics class do they teach all this in? I must have missed that one.... "Many worlds" is more philosophy than physics, isn't the most accepted interpret

What physics class do they teach all this in? I must have missed that one.... "Many worlds" is more philosophy than physics, isn't the most accepted interpretation, and even going down that path leads to lots of edge cases that could still imply impurity. Besides, if the world is pure, and OO is part of the world, then OO must be pure too so what's the problem?