You are arguing a strawman. Many-worlds is contended only conceptually correct, in the same way classical illusions of our billiard ball world are conceptually correct. Obviously, quantum mechanics is technically imprecise, and there is likely another conceptual picture that gives the more accurate layer of description of reality, in the same way as classical physics is technically imprecise, and quantum mechanics serves as a shift in perspective allowing to fix some of its imprecision (theories of relativity working on the same problem on the other end, and quantum relativity on both).

Reductionist analysis is not about getting to the bottom of things (it's pretty bad at that), but about moving between levels, finding simple patterns at the lower levels and using knowledge about them to reach conclusions at the higher levels.