The AOSP is fully open source. What you suggest is a significant step back in terms of privacy and security.
The AOSP does not run modern Android apps, since Google has been replacing the APIs those apps require with closed source versions (that only ship as part of Google Play) for over a decade.
alt Hacker News
The AOSP does not run modern Android apps, since Google has been replacing the APIs those apps require with closed source versions (that only ship as part of Google Play) for over a decade.