Can Epic pull this off? It already did

This is about a secondary point brought up: It's clear and unhidden large tech companies like Google, Apple, and Amazon rely on self-interacting ecosystems. This isn't always aligned with making a good product for the user. I wonder how many users are put off by this, and by how much- evidently not enough to stop using the services. What's the balance between raising profits by keeping customers in your ecosystem, and not frustrating them by breaking compatibility with outsiders?

It might be interesting looking at how Valve/Steam does it. AFAIK, they've built their model on working with outside developers. Started as in-house Valve games, and rapidly expanded to a majority of developers, including independent/small scale ones.

I'm finally looking forward to being able to unlock the iPhone, being able to ssh into it and being able to install features and widgets that aren't just Apple provided.

Hopefully this allow more companies to then allow sideloading of their apps without the stupid app store. Software delivery has worked perfectly fine on PCs for decades. It's time the phones joined in.