It’s the fastest way.
“Here’s my card. Call me”=1 sec
Get out phone, open contacts, start typing (how was you name spelled again, Schwarzenegger?)=way slower.
So, just using something digital is not always an improvement or more efficient. I tried differents tools since the days of the Palm (remeber IR contact data sharing, working one in 10 attempts?) and still prefer cards. Whats missing is a cross-platform, universal protocol.