With our chosen approach, people who think they know better can still disable the system camera app via developer tools which we strongly recommend against. We'll have stopped many users from unknowingly breaking other apps by installing an app like Google Camera and then disabling GrapheneOS Camera thinking that it provides a replacement for it. This is broken because Google Camera isn't a system app on GrapheneOS and therefore can't provide the system media capture intents which are only able to be provided by system apps. Similarly, installing GrapheneOS Camera on the stock OS and disabling Google Camera would be broken for the same reason. This Android 11 change is why this is the case: Please try to understand the explanation we've provided. Read https://developer.android.com/about/versions/11/behavior-changes-11#media-capture. Our release notes explain this and we've explained it here.
You wouldn't care about this if there was a mandatory component without a launcher icon providing the system media capture intents. You care because the app has a launcher icon and is thus user-facing. We could provide the ability to disable the launcher icon. Disabling the app as a whole is broken because it's the only way the system can provide the system media capture UI. It wouldn't make sense to bundle 2 copies of the camera app, one without the system media capture intents and one without the launcher icon. You wouldn't have a problem with it if we did which is what makes this strange. This app is a few thousand lines of code. You're fine with hundreds of thousands of lines of code you can't disable if it lacks a launcher icon.
The change was made because many users unknowingly broke these intents and caused app breakage, which led to both a support burden and issues for the reputation of GrapheneOS among app developers. All GrapheneOS users are hurt by people reporting spurious issues caused by misconfiguring their systems. Developers often end up blaming GrapheneOS and then won't provide support for it.
It's not reasonable to complain this much about something that's still optional but simply more strongly discouraged because it's broken. You're welcome to continue ignoring our explanation and to disable it.
People explaining that they disabled it and haven't noticed the breakage they caused, and aren't aware of what they broke are demonstrating why the change was done. When you tried to take a picture in an app and it crashed, you would not have realized you caused it and would have thought it was a GrapheneOS or app bug. The steady stream of issues filed by people who did this led to the change being made. Some apps developers blamed GrapheneOS and claimed it was broken because users disabled this and filed issue reports with them. We made this change because it's counterintuitive that you cannot replace system camera apps with non-system camera apps since Android 11, and therefore users were breaking other apps.