I also have Pixel 8a and have no issues with the camera. I'm by no means a photographer though and I don't think I have much of an eye for that sort of thing, but it works perfectly fine for my purposes, ie snapping a photo of anything interesting I see in my daily life, or if I want to show something to my friends by taking a picture of it. iirc the FOSS options don't give as high quality of a result as Google's proprietary camera app but all I need is photos to be legible so it's more than sufficient for me. If photo quality is very important to you then maybe you could use Google's camera app with sandboxed google play? I've never tried doing that before so I dunno if it works.