Claiming that flight search engines transform the impact of local events into a concrete reality is a superficial deduction.
These platforms are price calculators, not experience simulators; they do not describe whether a destination will be unlivable, only if the flight is more expensive.
For example, even if Google Flights shows exorbitant prices for Lisbon during the Festa de Santo António, it will never tell you if you can actually find a decent hotel room or a taxi.
True optimization comes from proactive research to anticipate these asymmetries between cost and experience quality, far beyond simple airfare pricing.