This is a very general statement because the impact of local events on travel planning is not always the decisive factor for everyone.
For many people, especially here in Senegal, budget constraints and available dates are much higher priorities.
You can't always avoid an event even if you want to; the trip sometimes has to happen, regardless of crowds or price, especially when it involves an essential family visit or an important occasion.
For example, a traveler may need to go to Dakar for a family event, even if it coincides with the Saint-Louis Jazz Festival, which could entail additional costs and crowds; the initial purpose of the trip will prevail.