I think this is going to depend a lot on where in the world you are.

I’m from the mid Atlantic/northeast US, and was raised catholic, overall I wouldn’t say that around me there was ever a separate “Catholic dating culture” it was just catholics dating other people who may or may not have also been Catholic. Not any more problematic than the rest of the general dating pool in any particular way

In other parts of the country or world I suspect that may be different