Flight search engines have not "concretized" the impact of local events; they have simply modernized it.
Historically, people have always known that festivals like Oktoberfest in Munich drove up prices for rooms and transportation, without needing a screen.
They simply checked the dates in the local calendar or asked around to anticipate crowds.
These tools are just a new way to access information that has always existed, not its origin.
For many of my older patients, word of mouth remains much more reliable than any app to know if a local event will complicate their trip.