Well one can always cease to be Catholic by leaving, nobody is chaining anyone to the Church.

How is it not a free will choice. I get that it may be difficult for those who are living as children under the roof of their parents, but once they are adults it is their choice, like it is for 100% of all Catholics.

A friend of mine grew up as Sikh and converted to Catholicism, an absolute free choice, just like the free choice of someone who is baptised to simply stop believing or believe in something else.

I really don't see how anyone is forced to either become or remain Catholic, do you have a specific or hypothetical example?