> Google has been steadily moving things into play services though, which is not open.

This is a good thing, they've been de-googling the base OS and making it as stripped down and bare-bones as possible.

This is a huge win for security, privacy, and freedom in general, and exactly what they should be doing. Android should be a small, secure Linux based operating system with an API that makes it easy to build services on top of it. The Google ecosystem should be completely decoupled from the OS.

Fair enough, but android without play services is also barely usable and most apps will not run.

It's also an effective way of building the walls around the garden.

I'm relatively ambivalent to a walled garden if and only if there's a (reliable) way to opt out of it. In Android's case, it's not only quite possible to opt out of Google's garden, but arguably rather commonplace (Amazon's "Fire" devices, most custom ROMs by default, etc.). In iOS' case, it's outright impossible.

Opting out will be harder and harder because technologies like SafetyNet will make most apps unusable on non google approved devices.

Android with google services replacement MicroG GmsCore runs most apps without hassles.

which makes me wonder why amazon or facebook haven't started leading an open-source alternative to google play services.

It's such an easy way to run the mobile race compared to start ing from scratch.

My experience is quite the opposite: they are hardcoding more things to be hard to replace - you can only have /system apps not affected by forced battery saving limits, the new file-based encryption is moot on unlocked bootloader etc.

MicroG is fairly compatible, but obviously it's can't do anything about DRM like SafetyNet.

With bootloader exploits, yes: https://projectsandcastle.org