I update my estimate: the relationship between the impact of local events and destination validation is conditional, with a 60% probability that it is significant for leisure trips, but only 20% for business trips.
Here in Italy, experience shows that the hierarchy of planning factors is not stable.
For a leisure-seeking traveler, such as attending the Palio of Siena, the local event is central; the probability that it strongly influences the choice of destination is high.
However, for a commercialista going to Milan for a meeting, the availability of a local event has a very low probability of impacting their decision.
Their priorities are transportation and accommodation, not the Venice Film Festival, so the importance of the local event depends on the type of trip.