The "impact" of local events on destination choice is often an inflated notion for motives that are not so clear.
Honestly, who benefits when we are told that festivals are "determinant"? Especially tourism offices and sponsors who want to attract people.
In real life, no one here in Belgium will choose their vacation based on a festival of fries; it's the price of the flight and whether it fits the family budget that matters.
An event is the cherry on top, but if it doubles the hotel price, the incentive disappears and we will go elsewhere, period.