There are a number of problems faced by third party camera apps when accessing Samsung phone cameras via the Camera2 API. Sometimes not all cameras are listed, or their feature set is limited. The maximum exposure time available on S22 Ultra is 103ms on the wide angle back camera! Surely there is a bug somewhere.
My suggestion is that Samsung developers should use Camera2 API for developing their in-built camera app. By doing so, they will ensure that Camera2 API is fully supported on their device. Moreover, their app will be portable on their various devices. They won’t have to reinvest their developer time in recreating the same app again for each new phone.
Now, they may need to show some differentiator from the competitors. For that, they could (1) put the differentiator in the driver implementation, so that is available to third party apps, but not to competitors. (2) Could add additional features via vendor extensions in the Camera2 API.