Does it affect the photo quality? It used to require letting go of the default photo app and thus a downgrade in photo processing.
I mean...... Google Camera has slightly different approach to low light photos and much better panorama mode, which means you can just install it and use with network access denied.
I mainly use native camera (good in most cases, can be brought up immediately with double power button press, from locked), Google camera (rarely), BlackMagic for when I need control over videos and ProShot when I need control over images (the last one might be hard to install - it's a paid app (I'm a paid user, this is how I got it), but not long time ago the moron of the developer made the app "incompatible" with devices without Google surveillance buttplug claiming it will prevent people pirating it form opening support cases....???).
So you can have multiple camera apps. Thankfully Google is not Samsung or Sony, and all the apps have full access to the cameras.
Install a 3rd party GCam and then the answer is no https://www.celsoazevedo.com/files/android/google-camera/
No, if you install the Google camera there is no difference in quality and by revoking network you don't lose privacy.