Your phone is the single most important privacy asset of your digital life. Therefore you should use the most secure consumer-grade phone.
GrapheneOS is a free Android-basedand open-source security-hardened and privacy focused mobile operating system . It is offering strong hardware security. It is compatible with several Google Pixel smartphones.
GrapheneOS improves the privacy and security of the OS from the bottom up and it never include Google Play Services or another implementation of Google services.