The idea that flight search engines can "realize" the impact of local events for travelers is too simplistic, it doesn't truly reflect how things happen on the ground. Historically, planning a trip around a major event required manual research and common sense, not just an algorithm. For example, knowing a festival will take place involves checking local calendars or talking to people, not just looking at flight prices. A comparison site can show a low price, but it doesn't tell if the streets will be impassable or if local restaurants will be overrun.
These tools are handy, but they don't replace local knowledge when it comes to adapting to a city in full buzz.