They didn't create most of the apps. Other developers did.Apple created the iPhone/iPad and iOS/iPadOS and the App Store. They're obviously not middle men.
As "agent" or "commissionaire", Apple are obviously acting as middle men between developers and consumers.
I'm buying an app that a third-party developer "submitted" to the App Store. And that third party will be providing customer support to me, not Apple. Yet I'm paying Apple (iTunes S.à.r.l), the middle man for that download.