I really don't know why we think we need permanent deacons.

There is no evidence that St Stephen was in fact a "permanent deacon".

Priests exist to bring us Jesus in the Sacrament of the Mass and in Sacramental Confession.

Just as we don't need "sisters" or "brothers" any more...given the education available to the lay (and the presence of the US Government safety net), there is very little need for Permaent Deacons.