Remember that your apps even if you use different profiles see the same IDs.

For instance data broker easly can connect them with you.

*Using GrapheneOS you're like a beacon on the ocean.*

Additionally GrapheneOS harvests data about you. 
They encourage you to use their servers on purpose. They don't have even an option to hide your real IP for instance updating OS, clock etc. via Tor.

They don't have .onion site.

GrapheneOS can be next CryptoAG.