At some point this IVF child will learn that several of his brothers and sisters in the petri dish were deliberately created and destroyed so that he might live. Some IVF procedures go so far as to produce in multiple children that are then stabbed to death in the womb. That has consequences. What lessons does the IVF child learn about his value to his parents if his parents were so willing to kill his siblings?
Also...You have created a strawman argument. No one on this board is saying that once life is created it should cease to exist.
Selective reduction is by no means a required part of the process of IVF.
Higher-order multiple pregnancies (more than twins) happens more often with IUI, not IVF, because with IVF the number of embryos replaced can be controlled—not so with IUI.