Look at the bulletins at smac.edu. The number of banns of marriage published is large. So it is working out for some people.
Like in many resistance chapels, a large chunk of those people who's parents maybe go but they go to SSPX or something similar.
Or some kind of romantic fascination with the resistance without the corresponding Mass attendance required.
In other cases they are sincerely resistance but just live far from a Mass, and so are genuinely unable to go.
Often though many of them are "mixed" marriages, meaning they are marrying a Novus Ordo person or indult/SSPX.