IDK, it doesn't seem ironic to me. Being the only store that sells something is pretty different from being the only store allowed in town.

They pay game companies to make sure they're the only store in town for popular new releases. There are other stores for other games, but not the Epic exclusives. Just like there are other stores for Android than Google Play, but lots of stuff uses Play Services and thus can't work without Play.

The obvious difference is that those game developers have the choice to be exclusive to the epic store, or steam, or neither or whatever. They are making the choice.

And game developers have a choice to not develop for iOS, but they do anyway.

It's not the same. Anyone who wants to develop a SaaS offering that requires a mobile app, which is basically everything nowadays, MUST take into account Apple's App Store and the Google Play Store because almost all of the target users will have those devices.

A game developer selling an exclusive to Epic is much different. They're not gatekeeping the platform which is the PC and no one is being forced to use the Epic store for distribution to get their games on the PC.

So to get access to 100% of the market on mobile platforms, you MUST deal with Apple AND Google. To get access to 100% of the market for anything on the PC platform you MAY deal with Epic, Steam, all of the above, or self-distribution. The difference is that developers get to choose which distribution strategy and platform makes the most sense for them in terms of cost, support, target audience, etc..

It's like if Walmart and Target were the only stores in North America and most buyers only shopped at one or the other. Would "choosing" not to sell your product at Walmart be a real option at that point?

The difference there is there is no other way to distribute iOS Apps. Period.

There are so many ways to distribute PC games and software, you cannot even begin to enumerate half of them.

Mostly the same on Android too. With a simple toggle, you can then install other App Stores like Amazon's, etc. Many phones come with alternative App Stores pre-installed too.