I didn’t say attrition overwhelmed the overall growth pattern. Most evidence suggests that it’s a proportion that increases with overall religious population, with compounding or confounding. factors (e.g. increasing or decreasing participation in a broader secular society).
Haredim “get away” with minimizing participation in many ways, which makes their attrition rates lower than comparable religious groups. But that doesn’t last forever; compare the secularization of Jews in Austro-Hungary in the late 19th century.
Modernization drew a lot of people away from traditional religion. But Hasidim and the Amish etc are "post modern". They have developed various cultural features to "immunize" themselves against the temptations of modernity. There is no reason for this to start failing at any particular point, except perhaps when they become too much of an imposition on the rest of society, which pushes back on them.
Haredim “get away” with minimizing participation in many ways, which makes their attrition rates lower than comparable religious groups. But that doesn’t last forever; compare the secularization of Jews in Austro-Hungary in the late 19th century.