The author in another article does recommend GrapheneOS.

https://madaidans-insecurities.github.io/android.html

“The best option for privacy and security on Android is to get a Pixel 4 or greater and flash GrapheneOS. GrapheneOS does not contain any tracking unlike the stock OS on most devices. Additionally, GrapheneOS retains the baseline security model whilst improving upon it with substantial hardening enhancements … includ[ing] a hardened memory allocator, hardened C library, [and] hardened kernel”