This is definitely not true. GrapheneOS is focused on privacy, security, and usability. It has many features that are solely for increasing privacy and control and implemented in very robust ways. For a couple of examples, see the Contacts and Storage Scopes features.

This is a common misconception people has as a result of misinformation being spread.

LineageOS also significantly regresses security compared to barebones AOSP.

• Userdebug builds
• No locked bootloader or verified boot
• Incomplete backports of patches