The way I see it there are two solutions to the “shidduch crisis”
1. You didn’t have such a crisis years ago because the average person didn’t have the means to send his son to Israel to learn. Lakewood and other yeshivos if they really want to solve the crisis should make a rule that they won’t accept any American boys who go to learn in E”Y first. Then the boys will be in America at an earlier age, satisfy the freezer requirement earlier, which indeed is necessary to weed out boys who just want to use lakewood for a few months for a quick shidduch and start dating earlier. Then those who want can go to Israel for kollel with a wife.
2. People’s shidduchim are preset for them when they are children like in the old days, then everyone knows that they are going to marry a certain person. Of course, if one side ends up having a problem (medical, drastic hashkafa change from family, etc.) then those people would need shidduchim like we have nowadays but the number would be drastically reduced.