Man, I love this OS. Review here: gemini://nnix.com/gemlog/34.gmi
I've been using GrapheneOS on an old Pixel 4a 5G for a couple years now. Nothing but great things to say. There's definitely a learning curve and acclimation period, particularly if you don't want to use the sandboxed Google services. But worth it to navigate and find FOSS alternatives to what you can.
You're right about the learning curve especially if one wants to go completely Google free. I tried FOSS app alternatives and slowly began adopting them before I eventually pulled the trigger and installed GOS. Although, I do have sandboxed Google Play installed on a secondary profile for necessary apps such as banking, I have to say that Graphene's implementation of Google Play Services and Frameworks is nicely neutered and easy to control so much so that I wouldn't have too much of a concern using it more often.
I finally de-googled my pixel 6a about two weeks ago and am using GrapheneOS. I absolutely love it. Best thing I've done to a phone.
GrapheneOS
An unofficial discussion community for anyone interested in GrapheneOS.
Helpful links:
Official Graphene OS Discussion Forum
List of official Matrix channels and other contact sources.