Wow....Your a bit heated and not needed...Sorry I crossed your path.If they have a balanced diet from a commercial feed, no they don’t need them. The same would go for ducks. But who are you to say they don’t benefit from it? There are a lot of vitamins and minerials in fresh fruits and vegetables. Even if it’s already provided in the feed it doesn’t mean they can’t get it from another source. Besides, eating from a raw source instead of a processed one often has several health benefits. Why else would people free range chickens? Isn’t not just so they can get exercise.
Putting aside all of that, the birds get enjoyment and mental stimulation from eating treats. I provide all the feed they want 24/7 but they still like getting treats. Mine get their treats tossed on the ground so they get to search around and hunt for it. It’s good for them this time of year since there isn’t much to forage. And even if I just tossed it on the composite pile like I do in summer, they would still go for it because they like it.