I'm on the fence about antinatalism. On the one hand, I think there's a fairly good case for it, mostly in David Benatar's asymmetry argument, and that most anti-antinatalist arguments are bad in that they tend to strawman the antinatalist position (which is why I've often found myself defending it).
On the other… Benatar himself has said that antinatalism runs counter to too many biological drives to ever be widely adopted. So maybe on an individual level your hypothetical child is better off not existing. But most people still going to have kids, i.e. humanity still has a future. And having kids is one of the ways you get to impact that future (by instilling values, etc). I don't think it's a sound idea to have a kid for one's own sake, and I certainly don't think it's sound to have a kid for their sake. But I'm partial to the idea of having kids for some cause greater than oneself* (provided there's a reasonably good chance of said kids having also good individual lives). As an ex-Muslim, it's also discomforting to observe that harmful ideologies can often be more fertile.
I also admit I'm sympathetic to Elon Musk's reason for being a pronatalist (or one of them, anyway). In essence, he's said that he's in favour of there being more biological (and artificial) consciousnesses because he thinks the more consciousnesses we create, the closer we'll be to discovering existential truths.
*though I doubt I'll have any myself. I think my genes are too problematic