The article describes the likely reasons. As the writer points out, it is odd that the USCCB is failing to look closely into factors why vocations are plentiful, or scarce, but the USCCB seems to be preoccupied with whatever issues the media is emphasizing this week.
We are reaping the effects of bad catechesis in most dioceses in the decades after Vatican II. Most young people were not exposed to absolutes of true/false, and right/wrong, but everything is relative. If the whole purpose of religion is to make people more happy, more equal, you can do that as a layperson.
We also see the results of bad liturgy and preparation. The Mass can be presented with devotion in the OF or EF, but if children are taught nothing about the Real Presence, if the Mass has no hint of the Crucifixion, little hint of any “Consecration” but is mostly the priest, and others, facilitating a Gathering Experience…well, you can be a social worker and do all that.
The Deemphasis on the Consecration, and on the priest in the confessional, eliminated a lot of vocations. The retired bishop of Lincoln strongly emphasized the priestly role in Mass, and confessions, so he fostered many vocations.