One thing I should point out is that now 85% of Jews worldwide are OTD. They became that way in the 17-18-1900’s. This was before the internet and TV. I believe even back then there were problems confronting modernity, and there were even fights over Torah and Mada in Europe in the late 1800’s. Making everything asur, and not accomodating, may have caused part of this.
But a big contribution was the terrible anti-semitism, poverty and discrimination in jobs that Jews faced. Most professions were off limits. I remember reading a heartfelt letter from a child in the 17 or 1800’s telling his parents that he loves them, but simply can’t make a living if he doesn’t convert. He begged them not to cut off contact. This was in a sourcebook from Rebbetzin Bleich’s course on Reform and Counter-Reform at Touro that somebody showed me.
In the 20th century the Young Israel movement has done much to keep kids in the fold, by having the Rabbi speak in English, not Yiddish, and making the davening relevant to American kids of the time. Not every “minhag” is worth preserving if it alienates kids. Today, the “minhag” of wearing black hats and white shirts may be doing the same thing that Yiddish speeches were doing 75 years ago. It is not an esssential part of Yiddishkeit, and may make certain kids feel self-conscious and out of place. We should focus on the heart, and not on superficialities.