I looked further into it and it seems to be because on iPhone the restrictions were purely technical, it just wasn't possible to publish anywhere other than the app store which apparently isn't monopolistic.

However Google were apparently making deals to make the play store the more attractive choice despite the alternatives existing, which did count as monopolistic behavior.

Now in isolation I can sort of understand both of those decisions, and I don't really care either way because fuck Google Apple and Epic, I want them all to lose. But in the context of both lawsuits happening pretty much at the same time this was literally the one result that made no sense. I could understand Epic winning or losing both cases, or even beating Apple and losing to Google, but this way round was just stupid and I think Googles recent behaviour is partially because of it.