It’s like saying since Google can modify some files in Windows that Microsoft doesn’t control the platform.

You complain that I’m not comparing like to like, yet you’re taking Windows, a closed sourced operating system, as an analog to AOSP, an open sourced one?

This is both because of differentiation

But why are other OEMs allowed to differentiate, and Google is not?

Yes, Google has the “official control” of how Android should be, and not all OEM changes are in line with that. But contributing upstream is not the only way to make the Android ecosystem open.

Take for example, Galaxy Watch with WearOS. There are multiple features that the watch can do, ONLY IF ITS PAIRED WITH A GALAXY PHONE. I have a Galaxy Watch 4. It has ECG and Blood Pressure sensors. But I can’t use it (officially), because I don’t have a Galaxy phone. Why? Because Samsung is keeping that exclusive with a software lock that totally doesn’t have to be there. Measuring ECG and Blood Pressure doesn’t need anything from my phone, it’s all on the watch.

Another example also regarding using Galaxy Watch with a non Galaxy phone, which is even more absurd, is that if you’re using a Galaxy Watch with Galaxy phone, they will sync DND status between them, but if you’re not using a Galaxy phone, it’ll not sync. They literally added codes for it to not work on non Galaxy phone.

Also, the example you used in your original comment, the call screening feature, uses language models that Google paid for the development and trained. I think it’s fair for them to uses that technology that they invested in to help boost their own profit instead of just giving out for free.

Stuff like call screening in the android dialer would be possible on any brand of device. But no, pixel only.

Other OEMs also have their own features that are exclusive to their own phones. They can also implement them into AOSP, but they don’t. Instead, they keep the features to their own devices. A lot of times when there’s a new feature on Android in general, more often than not you’ll see comments like “Samsung had this since years ago”.

So if other OEMs are allowed to have platform specific features, Google is allowed to have theirs too. Or in other words, if you want to hold Google responsible for holding back Android, you have to also hold other OEMs responsible too.