Ultimately, the ECB wants to get to a point where banks no longer want to use it for lending and borrowing, and the amountdeposited in its coffers hits the same level it was at before the financial crisis: zero.
Any revenue loss to the GRF would also decrease the amount of tax revenue that will be deposited to the Local Government Fund (LGF) and the Public Library Fund (PLF) for distributions to counties and local governments.