Google (and Apple) should have a say in what they sell in their storefronts. Suggesting that they have to carry any application submitted to them, law permitting, is taking the situation too far. Even demanding that applications submitted through the store use their IAP frameworks, at the 30% fee, feels alright to me.
The line is drawn at "is that store the only option". In Google's case, it isn't. Epic, and Android itself, has a road ahead of them getting users into alternative storefronts, but Android has the capability, and I think we're headed in the direction of alternative storefronts being the norm. This is especially true given that Google really does not control the hardware; Samsung has been working with Microsoft a lot lately, and being a Galaxy S20 user, I get a strong feeling that Samsung's relationship with Google is not a happy one.
The difference, of course, is that Android is an open platform and users still have multiple different options of installing Fortnite if they wanted to.
[0]https://www.theverge.com/2020/8/13/21368079/fortnite-epic-an...