As it was described in the previous articles, the user has to follow the 5 steps in order to make a deposit if they use a web browser and a crypto wallet on the same device. That is why the address should be presented as a link instead of a text string.
But imagine now that a user gets to a page with the payment form using their laptop and their crypto wallet application is installed on the user's smartphone.
At worst, the only way for the user to pay is to type every symbol from the address manually; the most likely outcome is that the user will leave the form without the deposit. That is why the QR code with the crypto address should be used at the same time as a link.