Mismatching billing to shipping details
When an order's payment details like the name and address on the payment don't match the name and address on the shipping details, it could be a sign of potential fraud.
Real ID can help save sales and prevent chargebacks by requiring ID verification on these orders.
If the ID matches the billing details, then you have evidence to prove the customer is the true holder of the credit card.

note
Within Shopify, this trigger is based off of the shippingAddressMatchesBillingAddress attribute on the order via the Shopify Admin GraphQL.