Earlier quoted context omitted.
They're just another representation of a long string or number... checking or verification can be built on top of it if needed by software.
They're worse because they're not human-readable. It's easier to trick someone into scanning the wrong QR code than it is to trick someone into sending money to the wrong url, email address, phone number, etc.
Most QR code readers (phone apps, at least) will decode the QR code and display the text before doing anything with it.