Android has 86% marketshare so it makes regulators nervous.

And Nintendo. And Sony. And Microsoft. And Steam. And...

And Steam?

Steam competes against GoG, Epic's game store, Ubisoft's game store, Microsoft's store, EA's game store, Blizzard's game store...

If you have an issue with Steam's cut you can simply sell on one of its competitors. Many companies do.

Yet Steam has a much larger share of the digital PC games market than Apple has of the smartphone market and the latter is being sued for anti-competitive practices while the former isn't.

Yes it does compete, but it's a very minor distinction in this case, IMO. And completely ignores everything else in my list.

iOS has Android? If you have issues, sell on Android.

I can use the same device/OS to install GoG or whatever. I need to spend hundreds to get a new device to use Android.

I'd say that's a fairly big difference. Whether that's enough to be considered a different market, I do not know, that's for regulators to say.

Judge's opinion [1]:

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Walled gardens have existed for 4 decades. Nintendo, Microsoft and Sony all had/have them. “What Apple is doing is not much different … they created a platform.”

“The 30% of what you complain seems to be the industry rate, right? Steam charges 30%. Microsoft: 30% … If you go to consoles: PlayStation, Xbox Nintendo all charged 30%. Physical stores: GameStop, Amazon, Best Buy, Walmart all charge 30%. Apple and Google charged 30%. It’s all 30%, and you just want to gloss over it. You don’t want to address it,” Judge Gonzalez Rogers says

--- end quote ---

[1] Quoted from https://edition.cnn.com/2020/09/28/tech/apple-fortnite-epic-...