APY, et al
The challenges we face face today are in essence an outcome of our successes.
When the frum community was small, it didn’t matter so much what your background was, it just mattered that you were frum. That was an improvement over the previous generation- my grandparents’- when there were so few frum people that it was no so uncommon for a frum person to marry a non-frum person.
Now that there are so many of us, just being frum isn’t enough- the pool of potential matches has to be narrowed to be effective, so people create the differences and nuances in types, schools etc.
Although there were good things about the olden days, we cannot reverse the clock, and we have to deal with the reality today, as nice as nostalgia is. (Also, don’t fool yourselves that there was no discrimination in shidduchim back then- I don’t think you would often see a Hungarian-Polish intermarriage, for example; there were factors back then that did matter that we would not consider important criteria today.)
Another thing, considering how many we are today, how mobile and inter-connected, a problem that affects even a small percent of our society translates into a large number of people, a critical mass that becomes very visible, hence a “crisis”. So even if the same percent of our community is not getting married as 40-50 years ago or 100 years ago (I don’t know if this is true- does anyone have data comparing today to back then?) it’s a lot more individuals.