So, I've managed to reduce my Pixel 9 with Graphene OS to the absolute minimum of necessary apps! Fewer apps, less battery consumption, less tracking.
I also deactivated all connections except for mobile communications, i.e. no NFC, no Bluetooth, no GPS, no permissions for the camera.
Now that I'm always sitting in front of my computer at home and have my ThinkPad with me when I'm out and about, I don't need a mail app, cloud connection or whatever on my smartphone, for example. I don't even take photos with it anymore, but unfortunately you can't deactivate/uninstall the Graphene OS camera app - for whatever reason.
Digital minimalism - a fine thing!