Even now that there is no undo button for transactions, a lot of people are still being scammed because they sent their money to a scammer or they sent to a wrong address.
Sending to wrong address doesn't means you got scammed, it's stupidity. That's why it's better to request for both qr code and wallet address of sender when sending a transaction. All you need is two devices, a PC and a mobile phone that you're going to send the coin from.