If you rely on the App Store, Apple has complete control over your distribution channel and take a large cut of your income.

Not only do they have control over your distribution channels, but the rules they impose change over time, forcing people into whatever Apple wants. There was a blog post on HN a while back where an App update was rejected because they failed to hype up the new iPad Pro's or another post where an App was rejected because (by sheer chance) somewhere the description referred to "an unreleased product".

The only real benefit is that it might bring your software in front of a lot of eyes, which, as a big player, you don't really need that much.