I'm a week into using GrapheneOS and its been great. It is a little restrictive in that I seem to have to explicitly allow apps to run and apps like my Bank app or Spotify don't work.

However, most apps are just Web Apps at this point and I've noticed very little difference in the use of the app versus the pinned browser version.

I'm also trying to curb a phone addiction so Graphene + Lemmy + Mastodon + Jellyfin is all I'm using on this thing.

I assume google headphones would cease to work if I degoogle the device

I'm using my Pixel Buds. They work just as well. Remember, its just a Bluetooth device just without all the QOL stuff like voice control.

I recommend trying it. Graphene OS install also has instruction ions to revert if you change your mind. And it's pretty easy. Maybe a touch harder than installing Linux generally, but if your dailying Debian, you're fine.