Wont change a thing...
Speaking as a consumer not a developer.
This will not change a thing for the vast majority of Apple users, we want an app for our phone we look in The App Store.
You want a subscription for your app? better have an ApplePay option........
Most of us picked Apple for the 'all in one place' simplicity of it.
Looked at from a Business point of view for company devices; probably a good thing, we can have our own 'company approved' app store except how many companies are going to bother?
Looked at from the viewpoint of a small developer; how many app stores do I need to support/use? expected response: F*** that! I'll stick to App Store........
The small very vocal minority who are calling for this will be pleased, the rest of us not so much because of "I have to sign up for ANOTHER app store? why?"
Now, if you make Xbox games run 'out of the box' on Playstation and vice versa then you may have a point......