These vocations are flourishing and will hopefully be able to assist the bishop in areas of need.
However, as you have pointed out, they are unable to say Mass, hear confessions, or administer the Sacrament of the Sick.
There is nothing inherent that says that a deacon cannot eventually be allowed to say Mass. The order of Presbyter (commonly known as priests) can remain as was originally intended as an assistant to the Bishop in a certain location. All three levels of Holy Orders, Bishop, Presbyter and Deacon, could, with a fiat from the magisterium, say mass, hear confessions........