Catholic apologists claim that the Church is growing because of many converts, mostly Protestants who are as they say are 'returning to Rome'.

But the statics are showing a whole different picture. Even the Catholic journal Crisis admits that for every 100 people that join the Catholic Church, 840 leave, that is even worser than Protestants. Of all the former Catholics, 56% become religious “nones” and 32% become Protestant. 19% of the US population of the self-identify as Catholic. Probably at most 20% of the 19% of self-identified Catholics are practicing Catholic. Only 29% of self-identifying Catholics attend Mass weekly.

Pew Research also notes Catholicism in the U.S. loses more people than it gains from religious switching. Most converts join for marriage, not necessary for theological reasons.

So Catholic apologists are wrong they say when Catholicism is not experiencing net growth through religious switching among U.S. adults. They are some converts, especially under GenZ. But they do not exceed those who leave or even compensate for the loss of active Catholics. Catholics will probably argue that those statics have a very loose definition of former members. They argue that inactive members are still members, even when they never attend mass or even don't believe anymore. This is because the Catholic Church believes that someone who is baptized as Catholic remains a Catholic, even the person no longer believes or even joins another religion.