Google gives you an App Store and maintain the OS that other hardware vendors (and sometimes themselves) implement hardware around. They take a 30% cut for distribution in their special app store and not much else.
Microsoft and Sony take similar cuts for access to their game consoles. In return they provide:
- High quality, robust developer APIs.
- High quality debuggers, graphics debuggers and CPU+GPU profiling tools with in-depth access to hardware counters
- Networking libraries for matchmaking, and a network backend for tunneling network traffic via their online services
- True development kit hardware with expanded resources for debugging tools
- High quality documentation and direct support
- GPU drivers that actually work
- Payment processing
- All for a hardware platform that is typically sold at or below BOM cost for the initial launch of the device
Google provides distribution via the Play Store, and only for about ~4GB of app before they force you to use your own CDN because they have a limit on the size of the app bundle they'll distribute. There's likely things I'm not aware of that Google provides for app developers rather than game developers, but if we're comparing to game consoles then I'm going to compare tool for tool.
Apple's tooling is better, largely because they have way more control over the target hardware and software environment, but they take an additional cost via their highly restrictive app guidelines.