A quick update from my end and opinion about "the best", at least for me.
If you are in the Stock MIUI ROM, and unless you really need some feature of the GCam, stay with the default camera app from Xiaomi.
It provides the best quality, have auto filters, AI optimization, and in 99% of the times will be even better that GCam. (I'm serious, just test it out and compare for yourself).
In other ROMs, i recommend the Gcam 8.2 by Greatness with the config "zainullahgcam.xml".
Here are the links:
GCam:
https://www.celsoazevedo.com/files/android/google-camera/dev-greatness/f/dl11/
Config:
https://www.celsoazevedo.com/files/android/p/f/2021/11/zainullahgcam.xml
The GCam can start a little "fuzy" after apply the config, but just restart it or restart the device and should be OK.
I think this provides the best quality possible. I cannot find any bug or issue and have been using it for weeks now. I am currently using ArrowOS 12.