That's what I thought as well. This a desirable but confusing feature which can't be addressed at the protocol level. It has to be interpreted differently at the front-end.
PMs could be end-to-end encrypted.
Does it send telemetry? Why is CalyxOS more secure?
Ever heard of RetroPi or Recalbox?
I've been running GrapheneOS on my Pixel 3 for three years and I have few complaints. I still cant figure out how to get automatic updates to work in Android 13 with the Neo or Droidify stores but atleast the stock GOS apps auto update. BTW, to clarify what you said, we have to use the Aurora app to download from Google Play Store.
You're right it's not for most people. Not having Google services installed might be a major blow for people who have become accustomed to the conveniences they provide. I just use a separate vanilla Pixel for Google services if I need them, but the phone with my SIM card is the one with GrapheneOS.