Why a contact code beats a printed number
A number printed on a card has to be typed, and typing is where contacts get lost: a wrong digit, a name saved as "Sharma ji plumber", a card left in a wallet. A contact code saves your name, number, email and company in one go, spelled the way you spell them.
It also works without the internet. The details are in the code, so the phone saves them even in a basement hall with no signal.