Hubsite vs digital business card
Digital business cards optimize swapping vCard-style details. Hubsites include contacts but also expect ongoing engagement: social and web links, downloadable proof, product menus, and scan history.
Overlap
Both use QR to bridge in-person meetings to something on the phone. Both benefit from short URLs.
Where hubsites extend the idea
When your card moment is also the entry to your portfolio PDF, restaurant menu, service catalog, or rep-specific deck, you need more than contact fields. The hubsite standard carries those sections without custom development.