[alt text: a bluesky text post by @cursedsynth.bsky.social. The post says: “honestly 2 eyes is a good amount. spiders can pull off 8. but flies got greedy. they were like: give me a million eyes. well, now you don’t know how to get out of my house”.]
Without being completely certain, I’m pretty sure arachnids don’t have compound eyes.
I think it’s mostly an insect thing.