Why ask why. It is uncommon that standard camera apps include QR scanning. Went through a lot, didn’t find anything, including a couple OEM cams (OnePlus, Essential).
Granted, I barely use cameras anyway.
I can’t recommend anything due to not much testing. For a long time I had settled on one and just stuck with it.
QR & Barcode Scanner (QR and barcode scanner with all the features you need.) from F-Droid.
Now for the caveats. The last version, 1.10, is broken. Seems intents or something is jacked up. It won’t open apps and behaves oddly in other areas.
Here is one of a few issues concerning that…
Can’t open links from the app with browsers, because “No apps found for this action” · Issue #138 · wewewe718/QrAndBarcodeScanner · GitHub
Version 1.9 works fine.
Another caveat. There is an app at the Play Store with the exact same name, from developer AppSourceHub. That app can be considered malicious and should be avoided. Some details about a number of apps that collect and send out data.
The Curious Case of Coulus Coelib – The AppCensus Blog
Sadly, the dev of the legit app takes heat from users who didn’t know they were not the same. Such as…
hey you know what? · Issue #153 · wewewe718/QrAndBarcodeScanner · GitHub