Ravens don't get in the way when I build. They don't shed light, so you can appreciate the balance of light in your build, they don't make ANY noise other than impacting enemies, which is nice, they can sweep crowds, making them good for lots of mobs, and they fly in a pattern that allows you to see what you are building. They aren't nearly as good/powerful as other end-game minions for boss-fighting or invasions, but when you want a minion that doesn't distract you, keeps the mobs off while you build, are silent, and are powerful enough to handle any biome, ravens are my choice.
As far as slaying Moon Lord, I haven't been able to use anything other than the Stardust Dragon, possibly my least favorite minion. It's just...so obnoxious.