If your sleep is absolutely perfect and you never have any issues with energy or anything like that, there probably isn't a point for you.

My sleep isn't perfect. I don't have insomnia but I'm terrible at keeping a sleep schedule on my own, I can have trouble falling asleep or I can be woken early for various reasons. The data helps me quantify these problems and act on them.

For example I can see that I was bad at adhering to my sleep schedule and try harder. If I didn't have this data I wouldn't know that there was a problem or how bad it was. If I had trouble falling asleep or woke early, I can check the app and see how much sleep I actually got and have an idea of what my energy levels through the coming day are going to be like.