Typical mind fallacy.
According to one estimate, there are about 250k total GrapheneOS users https://discuss.grapheneos.org/d/12281-how-many-grapheneos-u...
This source claims Google shipped 10 million devices last year https://coolest-gadgets.com/google-pixel-smartphones-statist...
If we generously assume every GrapheneOS user bought a new phone in the last year, 2.5% of those Pixels are running Graphene.