Arrows can penetrate many things that bullets can't.
I'm not "trying to get you" on anything. You made the above statement, and then didn't offer anything to back it up. I'm not sure what "crazy rifle rounds" are because the original post talked about 7.62x39 and .223. Pretty standard rounds.
Maybe I'll have my bow with me if I'm attacked by a bucket of sand or water. If it is flesh and blood, or a game animal, I'd still rather have a firearm. I've read that sometimes a blade or icepick-type weapon might penetrate body armor where it would otherwise deflect a bullet. An arrow might work here, depending on threat level. But with most body armor, cars, walls, etc, bullets will do a much better job than a shaft will.
I do have a good deal of bow hunting experience, and that has convinced me I need to be using a gun to hunt with.