i forgot who it was, but a heard that the concept of “tinok shenishba” barely exists in the world anymore because most secular jews are exposed to frumkeit somewhere along the line. i could find out for you if you’re interested.
i have a question on that too, though. what does “exposed to” mean? plenty of people are exposed to the wrong side of things and therefore perceive it in a bad light. kinda not fair to a guy living way out in hawaii who never heard of torah before in his life. does that count? i wonder.