Let's classify first, then judge: there is marketing segmentation and actual behavior.
Age segmentation is a useful category for targeting offers, but it does not directly dictate whether someone verifies their documents in advance.
A young person traveling for the first time will probably be very organized, regardless of age, while an experienced business traveler may delegate or ignore until the last minute, depending on their habits.
What really matters is individual experience and personal constraints, not the abstract age group.
In Berlin, even a student can be hyper-rigorous with their documents if an international trip depends on a complex visa.