Follow the prompt: who benefits from this idea that local events are so crucial for trip planning? Often, it is the tourism industries that want to fill their hotels and attractions during peak periods.
Here in Spain, the decision to travel is primarily dictated by ticket prices or school holidays, not a festival.
For most families, if a local event causes accommodation prices to rise by 50%, it is an expense to avoid, not a decisive factor to include.
For example, visiting Seville during the Feria de Abril is wonderful, but for a tight budget, it is a period to avoid if you just want to enjoy the city without breaking the bank.