"Customers must meet the following criteria to be able to sign up:
You must have a Steam account in good standing.
You must have made a purchase on Steam prior to April 27th 2026.
Limit one signup per household. We will use payment method, shipping address, and other information to eliminate multiple entries."That prevents flooding of tickets by a single person but doesn't prevent me from signing up even though I just want to resell
They took the same approach for the Steam Deck, so given that this is a repeating MO, anyone wanting to abuse the system had time to prepare accounts.
The payment addresses sound trickier to work around, but abusers can just invent a fake billing address; many payment methods neither receive nor validate this.