GrapheneOS is about unalienable rights and individual free agency.

Unalieanable rights are rights that come from God and cannot be taken away, not even by a 100% majority vote.

Unalienable rights cannot be legislated away, and they cannot be ruled away by a supreme court. They cannot be contracted away. Governments and institutions cannot add qualifiers to unalienable rights, and they cannot dilute them. None of these have authority over unalienable rights.

America is a country built on unalienable rights, not Democracy. The Constitution does not grant those rights. The Constitution explicitly tells the government that it cannot, and shall not, infringe on those rights.

The only way to guarantee your freedom is to not comply to tyranny.

Here's the Anroid Authority article screenshoted above that brings up additional reasons to use GrapheneOS: