Thus I aspire to proclaim the gospel not where Christ has already been named, so that I do not build on another's foundation, but as it is written: "Those who have never been told of him shall see, and those who have never heard of him shall understand."
Romans 15:20-21
Ping!
The problem is that the Church became a social services organization in Latin America, while the people wanted a religion. The only thing that has kept the Faith alive in Latin America has been the popular devotions, and of course the Vatican II bishops and clergy were very opposed to them.
Catholics either dropped away altogether, or went to one of the many Pentecostal or Evangelical churches that sprang up everywhere, mostly funded by US money. One of the big secrets of these churches, which boast of their “success,” is that they have a terrible retention rate, meaning that the “converts” stay only until the emotional high has worn off or perhaps only as long as the particular pastor they liked is there, and then they drift off, either to secularism...or to Islam.
The Muslims made great strides in Chiapas, for example, which had a radical leftwing Catholic bishop who drove away the faithful, who then became Pentecostals and then ended up becoming a windfall for the Islamic recruiters who are all through Latin America. This is because Islam offers them certainty and a law by which to live, no matter how distorted both of them may be, which is something the Church used to offer people until it became passe in the opinion of Vatican II and its clergy. People need it.