To start with op thanks for sharing this will definitely be of help to newbies who usually fall for this kinds of phishing scams. Ina case like this, mostly greed is what causes the victims to get scammed. Basically the victims would mostly want to visit the website so they can check and move any remaining funds there. Aside from that making use of these free SMS websites isn't really safe.
The pair ones that give you a private phone number for SMS verifications like this are still not 100% Safe but are still safer than these free ones.