Back in the days before Vatican 2, parishes had altar boys. Lots of them.
My own parish had upwards of 20 of them, and each Sunday they attended a meeting chaired by a priest, who allocated the Masses and other events for them to serve at. They were scheduled in pairs for two daily Masses, and then six weekend Masses, all of which were full, since in those days more than 80% of Catholics attended Mass each Sunday.. This by itself suggests that the bishops of those days were doing something right. And that the bishops of today, who must be doing something different, are achieving something rather less.
Altar girls were banned. In fact, no female was allowed near the altar (there were rare exceptions), especially when there was a priest there. Extraordinary ministers were likewise unheard of, even though the congregations were huge by today's standards.
Inaestimabile Donum (repeating the instruction of Vatican 2):
18. There are, of course, various roles that women can perform in the liturgical assembly: these include reading the Word of God and proclaiming the intentions of the Prayer of the Faithful. Women are not, however, permitted to act as altar servers.(27)
However, the Vatican seemed to repeatedly underestimate the disobedience of priests, and altar-girls intruded into the sanctuary some time after the end of Vatican 2, along with other abuses.
There would appear to be no disputing that around 80% of priests were formerly altar-boys. Boys who are attracted to service at the altar would quite reasonably be expected to be attracted to service as an adult.
And so it was. Vocations blossomed. Sure, we could always have done with more priests, and we did not know how lucky we were at the time.
With the influx of disobedient altar-girls, the boys started to go elsewhere. Young boys like to associate with other boys of their own age. When girls intrude, boys quietly vanish. And the resulting expansion of female presence was abetted by militant adult women who found themselves at last able to approach the sanctuary without being dressed down by the parish priest. In fact, the priests enabled these women through attempts to keep the peace.
We have seen situations where a priest tried to bring back some boys to balance the altar-servers, only to find himself facing an array of feminists. The priest backed down, and no more altar-boys.
This lack of masculinity among priests enables the feminists who are unable to see the consequences of their interference.
And we have bishops whose attention is focused on other matters. Laymen who can see the harm done are baffled that their bishop has not yet become aware that altar-girls are the cause of their failure to gain vocations.
So how did we get these altar-girls, forbidden by Vatican 2, and forbidden by Pope John Paul 2?
The approval of female altar-servers did occur under John Paul 2 (see the link below). There are some concerns over the scope of this approval. However, it has been accepted by bishops and priests. Yet a bishop retains the power to confine service to boys, and thus remove girls from the altar. Very few have done so.
So we bring in priests from Nigeria and India, both of whose nations have a huge problem with militant Islam, and need their priests sorely. And home-grown Australian vocations remain a fraction of what they used to be.
But not to worry. Attendance at Mass has also dropped, in some places down to less than 5% of the Catholic population. So the lack of vocations is not so noticeable.