> It is still competition even in this context, it just happens on a slightly slower cadence. The Apple customers, by and large, are paying good money to avoid Google's app store because they believe Apple is a better steward on net.

You're looking at a different market. The customer in this context is Patreon and the product is app distribution. Patreon needs a way to distribute their app to all of their customers. Many of their customers have iOS, so Patreon needs app distribution to customers with iOS, and there is only one supplier of that.