[bitten]

Pixel user here too. You have to enable "Google Lens suggestions" in the camera settings for it to read QR codes automatically.

Drop down menu > Camera Settings > Google Lens suggestions.

[SethMurphy]

In addition on my pixel 3 you can open camera app and long press QR code. This works with or without enabling lens suggestions.

So, double press power button, long tap QR code, and click link to visit site.