my biggest gripe with QR codes is that the built-in camera apps on smartphones dot not scan for them by default. Instead I have to hunt through my installed app

my biggest gripe with QR codes is that the built-in camera apps on smartphones dot not scan for them by default. Instead I have to hunt through my installed apps to find the "barcode scanner" or whatever. Why can't the default camera recognize a QR code, either in preview or after taking the picture?