“Catholics who move to another Christian denomination do so because they want a deeper relationship with Christ and faith”
You can have no more “deeper relationship with Christ” than actually being in His presence in the Holy Eucharist.
No devout Catholic could possibly abandon Christ for any other faith. Impossible.
If they left, they never believed in the real presence to start with, and certainly were not devout Catholics.
That is your belief, and an argument that you can have with them about church denominations, but you should strive to be more accurate when describing their reasons.
“Nor are the people becoming Protestants lazy or lax Christians. In fact, they attend worship services at a higher rate than those who remain Catholic. While 42 percent of Catholics who stay attend services weekly, 63 percent of Catholics who become Protestants go to church every week. That is a 21 percentage-point difference.
Catholics who became Protestant also claim to have a stronger faith now than when they were children or teenagers. Seventy-one percent say their faith is “very strong,” while only 35 percent and 22 percent reported that their faith was very strong when they were children and teenagers, respectively. On the other hand, only 46 percent of those who are still Catholic report their faith as “very strong” today as an adult.
Thus, both as believers and as worshipers, Catholics who become Protestants are statistically better Christians than those who stay Catholic. We are losing the best, not the worst.”