I own an Xperia 5iii (so about four-and-a-half years old now), and I also own a Pixel 10.

The Pixel 10's camera is unequivocally better. The JPEG outputs are processed, 'Instagram-ready'. The output from the Sony camera even in JPEG mode is considerably more muted, neutral, and has less contrast. Note that this is not representative of newer Xperias' camera quality; I've heard they have improved considerably. I'm not too concerned because I hardly use my phone to take photos; I have a Nikon mirrorless for that.