How's the camera on Pixels w/ AOSP roms? I haven't installed a custom ROM in years now, and my last experiences were on Samsung where custom ROM means destroying your camera's picture quality.
On Pixel and Nexus phones, the Google Camera app works properly if you have either microG or Google Play Services installed. If you're using microG, you'll need to install the Google Camera app manually:
https://www.apkmirror.com/apk/google-inc/camera/
The camera quality and features are the same as in the stock ROM.
Google Camera is proprietary, but you can disable its internet access through the app settings (in LineageOS) or a firewall like AFWall+:
https://github.com/ukanth/afwall/
If you're using another camera app, then you'll lose Google Camera's optimized features. This may still be worth it if you prefer to use FOSS software.
It works quite well! Having not used 'normal' Android (anything that's not Lineage/Cyanogen) for years, I attempted to start out using this phone with the stock Google Android build. I disabled all the bundled crapware (Play Music, Play Movies, Play Games, YouTube) and they all kept re-enabling themselves. If you're looking for a device that will help you avoid Google at least a little bit, look at this page first. https://wiki.lineageos.org/devices/