I think it's reasonable for regulators in the long run to rein in these cash cow businesses a bit, when they're a crucial bottleneck in an ecosystem, just like

I think it's reasonable for regulators in the long run to rein in these cash cow businesses a bit, when they're a crucial bottleneck in an ecosystem, just like long-duration patents or copyright. The extra fee likely stifles innovation, just like any tax or overhead to setting up a business. Both Android and iOS are not actually that dependent on App Store revenue to stay afloat, and I think courts will (and should) continue ruling this way in more consumer-friendly locales. Apple still makes more of its iOS profit from device sales, despite its attempts to increase services income. Google actually makes more of its profit from ad sales to users on Android phones than from Google Play Store itself. The development cost of Android is likely quite a bit lower per user than what Google has to pay to Apple to keep Google as the default search engine. As such, Google still has a strong incentive to keep developing Android and promoting it so it gains market share from iOS.