Google further guts the Android Open Source Project by deprecating the dialer and messaging apps

It's no secret that the Android Open Source Project has been languishing compared to the distributions (?) of Android that are actually being used by Google itself (on their Pixel phones) and OEMs such as Samsung, Sony, and others. Now, it seems Google has taken a pretty substantial step in further gutting AOSP - it has deprecated both the Dialer and Messaging applications in AOSP, with the following message:

This app is not actively supported and the source is only available as a reference. This project will be removed from the source manifest sometime in the future.

This means that soon, if you build the Android Open Source Project, you will no longer be able to send messages or make phone calls without adding your own messaging and dialer applications. In the grand scheme of things, this doesn't matter all that much since every OEM already uses their own applications, but for the open source operating system that is Android, this is another nail in the coffin. Due to the slow erosion of functionality from AOSP, as well as the transfer of functionality from AOSP to closed-source Google applications and frameworks, we're fast approaching a point where you can't really state that AOSP is a full open source mobile operating system anymore.

Is a mobile operating system that can't send messages or make phone calls really complete?