Camera quality depends on both the camera firmware blob and the camera app. On high-end Android phones, the camera app usually makes use of proprietary features on the firmware blob and performs post-processing (such as HDR and bokeh).
Other Galaxy S7 (herolte) users seem to have the same problems as you on LineageOS, but it's hard to tell exactly what causes them:
Google Camera's post-processing has been well-received, and the app has been ported to many non-Google devices, including the Galaxy S7. I'm not sure how well the S7 ports work (especially if your S7 has an Exynos SoC) but XDA Developers has a couple of active threads here:
Using one of the ports might improve your camera situation. No guarantees, but it doesn't hurt to try.
I recommended the first-generation Pixel and Pixel XL because they are the only phones that are currently supported by both LineageOS and the latest version of the official (non-ported) Google Camera app. For people who aren't particular about camera features and quality, the Camera app that comes with LineageOS or any third-party camera app would be adequate, and you can use these with any supported device.
Other Galaxy S7 (herolte) users seem to have the same problems as you on LineageOS, but it's hard to tell exactly what causes them:
https://www.reddit.com/r/LineageOS/comments/8awrcz/herolte_g...
Also, the Galaxy S7 is no longer officially supported by LineageOS, since there are currently no active device maintainers:
https://wiki.lineageos.org/devices/herolte/
It's difficult to diagnose issues with unofficial builds of LineageOS, because they most likely don't meet the LineageOS device support requirements:
https://github.com/LineageOS/charter/blob/master/device-supp...
Google Camera's post-processing has been well-received, and the app has been ported to many non-Google devices, including the Galaxy S7. I'm not sure how well the S7 ports work (especially if your S7 has an Exynos SoC) but XDA Developers has a couple of active threads here:
https://forum.xda-developers.com/galaxy-s7/themes
Using one of the ports might improve your camera situation. No guarantees, but it doesn't hurt to try.
I recommended the first-generation Pixel and Pixel XL because they are the only phones that are currently supported by both LineageOS and the latest version of the official (non-ported) Google Camera app. For people who aren't particular about camera features and quality, the Camera app that comes with LineageOS or any third-party camera app would be adequate, and you can use these with any supported device.