The short answer is, unfortunately, nothing.
The long answer:
Apple's App Store policy is notoriously controversial for being overreaching. Apple built a tight vertical integration of the iOS ecosystem. They control everything—from distribution to payments to customer relations—by design.
This tight control Apple employs certainly benefits users, but it mostly benefits Apple. The App Store is hugely lucrative. Developers, however, are sick of having to put up with their policies.
Epic Games recently threw a major stunt against Apple, after months of trying (and failing) to negotiate better rates. Epic is the maker of Fortnite, a massively successful online game with a huge fan base. By "forcing" Apple to remove the game from the App Store, they'll drive the swaths of Fortnite enthusiasts against the iOS Goliath – and hope that will give them some leverage in the negotiation.
Epic is joining a list of major companies (including Microsoft, Spotify, Facebook, Airbnb, ClassPass, and Basecamp) with a beef against the App Store. The main question I'd like to address is, how does that benefit us, independent developers and development studios? What changes for us?
Ideally, Apple would back off from enforcing payments through its payment system and keep control of distribution only. Their oversight of iOS Apps has always been highly beneficial to customers, after all. That would give freedom for us, developers, to use external payment processors (hello, cross-platform Stripe integration!) and not pay the 30% fee Apple charges for every payment made through their platform.
Less desirable but also beneficial would be if they kept control over payments but lowered their fees for everyone. I believe this option (and the previous one, for that matter) are highly unlikely to happen. After all, these were the policies that made Apple the most valued company in the world, with a \$2T market cap and trending up.
The least desirable and, in my opinion, most likely outcome is Apple cutting a deal with Epic (like they did with Hey). Life will go on - as in, every independent developer or small studio without a huge fan base will keep struggling to build a sustainable business on the App Store.
Evidence that Apple doesn't intend to budge is their latest move, threatening to revoke Epic's access to developer tools. That means the Unreal Engine, a game engine developed by Epic and widely used by game developers filmmakers, will stop running on iOS. This move will likely drive more developers and gamers to join Epic's cause. It shows Apple isn't trying to de-escalate the fight. They're throwing gas into that fire.
Developers are scared of Apple. They say the App Store policies are arbitrary and are afraid a change can put them out of business. Unarguably Apple policies need an overhaul if they want to attract more developers into their platform. Unfortunately, I'm skeptical that would happen.
Apple currently doesn't have a financial incentive to change. Also, not many developers or dev studios can afford to ignore a user base of nearly 1.5 billion active iOS devices. Us, developers, are caught between a rock and a hard place, and we can only hope Apple will find space for us in their hearts someday.