Asking “why” questions about our body / evolution often (not always) gives informative answers. As in the example you gave: https://www.scientificamerican.com/article/the-purpose-of-ou...

Interesting finding, though it doesn't explain animals with properly-wired retinas: https://en.wikipedia.org/wiki/Cephalopod_eye

(Scientific American is throwing up a paywall even though they're only republishing https://theconversation.com/look-your-eyes-are-wired-backwar... At least they link to the original.)