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........
In the very early Church, before presbyters, there were Bishops and Deacons. The deacon at that time was an assistant to the Bishop and his ministry was one of service. Acts of the Apostles describes the first process that established the diaconate.
As time passed, the office of deacon became a transitional office, that is, it became a step in the process of ordination to the presbyterate. It eventually disappeared except in its transitional aspect.
The office of the permanent deacon, that is, a deacon ordained to be a deacon and not as a transition to the presbyterate, was reestablished at the Second Vatican Council specifically as a office of service. It was not, nor has it ever been, considered to be a sacerdotal office.
So, no, permanent deacons cannot offer the Sacrifice of the Mass, the Sacrament of Reconciliation, or the Sacrament of the Sick. Nor are these sacraments reflective of what the diaconate was historically. They can currently baptize (as can anyone in an emergency) and witness marriages. The matrimonial witness is an interesting one since the Church views the ministers of the Sacrament to be the couple with all others serving only as witnesses. You will not see a change in the sacramental role of the permanent deacon and it could not be changed in the way that you have described.
Priests, on the other hand, could be allowed to marry if the Church was to see fit. Celibacy is a discipline and a great gift to those who have been given it although it has its challenges. Although THIS could be changed, you and I will never live to see it if it eventually happens.