In the filing Epic tries to define an "iOS App Distribution Market" and an "iOS In-App Payment Processing Market". The suit will probably turn on whether the court accepts those definitions or not.
Epic attempts to argue that the "iOS App Distribution Market" is a separate market from the overall app market, but if you look at their arguments, they apply equally to the video game market.
- Games are platform specific, games developed for Xbox cannot substitute for games designed for Nintendo.
- Users face substantial switching costs when switching platforms. They have to buy a new console and then replace all their games.
- Each company controls the distribution of games on their respective platform.
When you look at video games are they three separate markets of "games for Xbox", "games for Playstation", and "games for Nintendo"? Or are they three separate competitors competing in the global market of "video games" despite the above constraints?
I think Epic is going to have a difficult time convincing a court with this argument.
The relationship between game and console makers, and the one between console makers is very different than one between app makers and Google/Apple.
Game studios and console manufacturers have historically negotiated on relatively equal footing. It's as important to console makers that game studios make games as it is for game studios to have access. So studios are courted and get a relatively fair shake. Apple/Google don't care if you don't make an app for their system. They're not giving any discounts or incentives to app makers.
Console makers also are in a more competitive market. There were usually three makers plus near competitors like PC, web, and arcade gaming. Plus, not owning a console was an option.
On the other hand Apple/Google barely compete with each other. Pretty much everyone is going to buy a smart phone and they're the two options. They're a cushy duopoly with no incentive to rock the boat.
Be that as it may, it's not really relevant to the question of whether Apple requiring apps to be distributed by their own App Store constitutes an antitrust violation.