GrapheneOS still does more for security:

• Even if an attacker disassembles a Graphene phone and reads everything off the memory chip, all data will be encrypted with your unlocking passcode. Then it’s just up to how long it takes to brute force it open on a server farm. I’m not aware how exacly /e/OS is encrypted.
  On the other hand, Google Pixel phones have suspicious hardware:
  https://lemmy.world/post/27344091

Hardware-level components like Titan M can execute processes that users cannot audit or disable, raising concerns about opaque data collection.

• Graphene installs security updates against online attacks the fastest of all. /e/OS promises “typical relaxed vendor pace”.