The shtetel experience was such that 2 people from the same or neighboring towns had the same background and experience. The close “bungalow-colony”-like atmosphere ensured that people knew the girl quite well. Today’s large cities and divergent backgrounds make it that you need more time to get to know the person, and make sure that no serious problems are being hidden.
To be clear, I do agree that much of today’s hishtadlus is excessive. My rav put it this way- check into a girl the way you check into a job. Both are bashert, but people do much less checking for jobs than they do for shidduchim. No matter how much research you do, there will always be adjustments to be made. As long as you are willing to work it through, that is marriage.
Another example of the change in frum society due to the move from the shtetl is what is today known by the misnomer Glatt kosher. While in Europe, people would eat cows even if there were large lung deformities, they relied on the lung checker, who was known by the rabbi. Today, most people do not eat meat unless it’s glatt kosher, meaning that the lung deformities are minor. (A totally smooth lung is known as Beis Yosef Glatt or genuine glatt). The reason for this change is that due to the massive operations in today’s slaughterhouses, it’s impossible to personally vouch for any lung checker.