Why do you think that GrapheneOS cares about your privacy?
It's only a marketing and PR gibberish.
For instance.
- GOS is an excellent tool for fingerprinting users. They promote using webinstaller, don't warn people about fingerprinting.
- GOS doesn't have .onion or i2p sites.
- GOS has no option to update apps/system viaTor or I2P.
-GOS forces to use their server if you want to have accurate time on your phone - nowadays it's crucial.
...
Your constant traffic to GOS servers can be monitored.
DivestOS is not ideal but it has more privacy features than GrapheneOS.