Earlier quoted context omitted.
GrapheneOS is in some ways not an open OS. The official builds don't provide root access. So for example apps are able to hold your data hostage from you. I get that this is in the name of security hardening. And you can make a build that has limited root access and is officially supported. But GrapheneOS isn't the end-all solution to computing freedom. Although hopefully on those devices you will be able to install…
GrapheneOS is all about security, not privacy or freedom. You coincidentally get privacy and freedom benefits, but only where they don't conflict with security.
GrapheneOS doesn't make any connections to Google or Qualcomm by default, unlike all the other other Android-based systems. https://grapheneos.org/faq#default-connections
See https://eylenburg.github.io/android_comparison.htm
As previously mentioned, GrapheneOS hosts a proxy for the Qualcomm SUPL service. In addition, it removes unique device identifiers from the requests, that would normally be present.
GrapheneOS supports the Pixel tool for provisioning eSIMs, but it's fully sandboxed and doesn't share any data with Google.