Ah yes. I don’t know the nitty gritty details, but it probably provides serves for auto-updating your app. Usually every permission that an app has can be explained as required by one of their features (your SMS may be able to send media, i.e. recorded messages), but when they are granted, they implicitly allow many other uses at the same time.
Some free apps though, are really abusing permissions, like a free flashlight app, that contains thousands of trackers. A way to check if there are trackers in an app was presented by @valere, who also created an app for that. See: Exodus Privacy / behaviors which can be dangerous for user privacy