The way Epic boycotted Android (and Mac) was always weird. The only platform that really prevented them from working was iOS, because you couldn't sideload it. You CAN but it's a pain in the arse and not really suitable for most people (though, it's not hard). Epic could have shown people how to do it and continued to offer their game on iOS, and sold the V-bucks directly to users, and Apple couldn't do shit about it, unless they stopped how sideloading worked, and some say they would never do that because it also allows developers to test apps. But they might. Apple never did anything to prevent them from offering the Epic Game Store on macOS. They just removed it for a while. It's back, you can use it, even filter by OS and install/run games from it, just like Steam. However, Fortnite is listed as "unavailable" for some reason.
It's worse on Android. Just like macOS, users have always been able to install the Epic Game Store on Android and get Fortnite through that. So, what's the big deal, on macOS and Android? See, hosting big files costs money. And Fortnite updates every couple days. So Epic doesn't want to have millions of people downloading Fortnite, if they can help it. If they can upload the update once to Google and let Google handle the downloads, that's better on them. But they don't want to pay Google in terms of letting them take a cut from sales of their virtual currency.
On one hand, yeah, "rent seekers" like Apple and Google are kind of in the wrong... but their costs aren't zero. They want Apple and Google to host their game effectively for free. They've always been able to offer it directly. They just wanted others to host it for free. So next time you see Fortnite update, think about how many people are playing, and do some basic math, and look into what hosting something with that much bandwidth required costs, and you can see how much Epic is trying to mooch from Apple and Google.
But let's be absolutely clear, everyone's an asshole here.