J.D. Flynn counts the number of sees becoming vacant, and offers a compelling argument over at The Pillar: 

The unique challenge for the Congregation for Bishops, several Vatican sources have told The Pillar, is that an increasing number of priests feel comfortable declining an invitation to become a bishop, a decision that was far more uncommon until recently. And bishops already leading dioceses have also grown more comfortable declining appointments to new dioceses.

Diocesan bishops face a growing spectrum of challenges in the U.S.: dealing with the internal ecclesiastical fallout from the 2018 McCarrick scandal, addressing declining religious participation in the U.S., declining diocesan revenues and expensive upkeep and administrative obligations, a scrutinous public spotlight, and the challenges of legal and political environments perceived to be increasingly hostile to the work of Catholic education, charity, and evangelization.

Those factors have played a role in recent efforts to fill the Diocese of Duluth, sources have told The Pillar, as well as the Diocese of Helena, Montana, which was vacant 20 months before being filled, along with the Diocese of Buffalo, which was vacant for a year.

If it remains difficult to find willing candidates for the episcopacy, dioceses may find it increasingly common to wait considerably more than a year for the appointment of a new bishop. And of course, backlogs have a way of growing exponentially.

The challenge of filling vacant sees points to broader challenges for the Church, among them a contracting Catholic population in some parts of the country, and declining religious practices in nearly all parts. Those realities may suggest to the Holy See a move which some U.S. bishops have been quietly suggesting to Rome for quite some time: more frequent consideration of diocesan mergers…

..The situation means that many dioceses are in the position of supporting a diocesan infrastructure — chancery, tribunal, central school administration, social services apostolate — with fewer dollars, fewer priests, and fewer practicing Catholics. That administrative challenge may well be among the disincentives for episcopal candidates, especially among those dioceses which are in bankruptcy.

Read on.