Yeah, Google has stopped developing the aosp apps that we consider core phone os functionality (dialer, contacts, etc). Because usually when aosp is forked and distributed, those apps are supplied by the distribution and unused.

It sucks and it puts more effort on the rom devs. But tbh we're many years into this, I'd prefer Google focus on the core os efforts and let the distributions take care of the app bits of the OS. Not totally unlike how linux focuses on the kernel only, and the apps that make up an os as we see it (browser, file manager, etc) are handled by others focused on building those bits (ie KDE, gnome, etc).