Direct API connections to separate banks are Painful, Difficult and Expensive.
Aggregate make it easy for your business applications to connect to different banks.

Due to deadline of PSD2 launch, each bank will have “their own API” to offer.
It will be a headache for your business, as you must then make a separate contract with each bank.

It will take time and money alone to get access to the bank API. Then the real headache begins, connection-test-compliance, not to mention the expensive tranaction fee beside the contract fee.

 platform eliminate the necessity to connect to each separate bank, as you connect
all your business application through one platform to access to all banks with one connection.