Originally Posted By: tfabris


... We have become accustomed to doing this kind of thing in our desktop operating systems, so it's natural for us to want to do it on our phone operating systems.
For many, many people, they have no such thing. Mobile first, and often mobile only.

And not in the mobile browser either. Natural often just means what you are used to, from the past.

Allowing non-Apple apps to become the primary/default app for a core iOS function (especially something user facing like email) risks boxing Apple in and limiting their ability to rewire iOS in the future. Creating public API and methods that third partys can use to replace core app functionality creates real future limits on how quickly or quietly Apple can internally pivot and evolve the platform, especially if they must cajole other companies to follow along and continue to support (for some amount of time) those companies that prefer the prior method.