You immediately see the problem: if nobody is borrowing, there is nothing to report, and the rate on which international finance is anchored disappears. That is what has been the case since 2007, when commercial banks began to withdraw from the short term market for funds.
The benefits of a harmonized and integrated cards market are way too obvious to oversee: standardisation, integration instead of current fragmentation and more competition, means more choice for consumers (which schemes to use), more choice for banks (which schemes to issue and to acquire and which processors to use as well as access to cheaper technical infrastructure due to standardisation), more choice for retailers (which schemes to accept) and more choice for infrastructures (which schemes to process).