This is a single metric. Number goes up. What other numbers went up? What numbers went down? What do these directions mean?
It does seem like fewer child deaths is a good thing. It does seem like modern medicine in general is probably a really good thing. There are a lot of other things in this world that are good things.
I'm not trying to deny goodness here. Just asking for more perspective, to better mitigate hubris.
https://ourworldindata.org/much-better-awful-can-be-better