Every time I purchase things online with a credit/debit card the checkout page asks for my CVV number. It is absolutely guaranteed that said CVV entry box has a little [?] next to it to help explain to users what this number is and where to find it.
According to Wikipedia, this number was developed as early as 1995 [0], meaning we've had over 2 decades to become used to them.
So from a technical and design perspective, why don't more forms omit this? Why do we still need to explain this to shoppers? Can't we just put a little lock icon next to the CVV on a card, and then put the same icon on the site. This way that field can be visually matched by the user. From a user experience / product design standpoint, why aren't credit cards better designed to convey this information naturally?
[0] https://en.wikipedia.org/wiki/Card_security_code