Attention is the bottleneck, and the idea that local events are a decisive factor for most trips seems simplistic.
The reality is that resources like time and money are finite for most people.
We cannot consider everything, and budget and leave days are much stricter constraints than the presence of a festival.
For example, a family with a limited budget in Montreal will first look for an affordable flight and family hotel, not a specific jazz festival, because their liquidity is limited.