Why choose LineageOS over GrapheneOS?
Graphene devs seem to move faster and provide more security. They made the Pixel9 images really quick and everything is working good
Discussion
grapheneos is another class of security and UI, it feels really an operating system in daily usage and the attention to details is incredible. Lineageos instead vary a lot from device to device, and in general is a lot less polished and secure. But it permit to free from spyware a lot of devices and gain control over it...