3DS 2.0 is an improvement of 3DS 1.0 because it:
Collects more data elements than 3DS 1. This helps issuing banks assess risk more efficiently by reducing the need to ask for more authentication from the cardholder. It also helps increase the rate of frictionless transactions and decrease the number of authentication challenges during a transaction.
Supports mobile clients. By adding support for native iOS and Android SDKs, cardholders have a smoother mobile authentication experience without requiring redirects or webviews.