Comment by grapheneos

RCS is fully functional on GrapheneOS with an app supporting it. Google Messages is the only RCS app for Android available in practice. It fully works on GrapheneOS via the official sandboxed Google Play compatibility layer support for it.

Camera features and quality on GrapheneOS are the same as the stock Pixel OS within the same app. Pixel Camera fully works on GrapheneOS even without sandboxed Google Play in the same profile.

GrapheneOS fully supports dual SIM and cross-SIM calling. It has much better support for it than the stock Pixel OS because cross-SIM calling is one of the features which can be force enabled for carriers not usually supporting it with the GrapheneOS carrier overrides. That also applies to 5G, VoLTE, Vo5G and VoWiFi where those can be used on carriers where those aren't available with the stock Pixel OS.

> but GrapheneOS really doesn't seem ready to be a daily driver

GrapheneOS is a daily driver for many people. The 3 things you've listed as concerns work at least as well in GrapheneOS as the stock OS. You're assuming functionality that's available is missing.