Why did you send a QR code instead of an ordinary text message after the scenic spot ticket was paid successfully?

Because the confidentiality and anti-counterfeiting of QR code are better than SMS.

In terms of cost, convenience and expense, SMS is definitely better. However, short messages are easy to be faked. Just send the same text message with the same operator's number. For example, if you use 106 123456 to post your company's product group purchase information, if I know which SMS company can post this 106 123456, I can post fake news as your company. So keep it a secret,

Security is not as good as QR code. I just gave a simple example.