The Pixel 3a's major selling point is its camera performance, as it was marketed as being on par with the more expensive, flagship Pixel 3 phones in that regards. Thankfully, DxOMark seems to agree.
https://www.notebookcheck.net/DxOMark-The-Pixel-3a-s-camera-is-just-as-good-as-that-of-the-Pixel-3.427895.0.html