Another advantage to a pilgrimage festival is that a "critical mass" can be achieved. Many traits in life are distributed in what is called a bell curve. Most people are average, but some are extraordinary. Some are less than average. Almost any group will have a few musically talented people, a few people who are very good with children, and a few people who can speak well. The larger the number of people in the group, the larger the number of people with these talents that will be available for a festival.
So if a number of congregations come together, the talent pool will be substantial. To use one extreme, if you camp in your back yard, you are not going to achieve critical mass.
What does a festival need? I can only speak for, or maybe better to, my tradition but it seems to me that you need 8 speakers, 8 singers for special music, 8 teachers for a children's program and so on as the fall festival lasts 8 days. A newer innovation to festival observance is seminars for adults. You would then need multiple presenters. While it would not be a tragedy for a person to speak twice, it is better to have a wild variety of people that serve.
The principles I have been discussing do overlap, and are sometimes in tension with each other as we will see. In order to achieve the principle of worship in its fullest form you need a critical mass. Combining several congregations into one pilgrimage feast can accomplish this.
I see no reason to despair with the feast site you attend if it does not meet my utopian expectations. You soldier on, and DTBYC—do the best you can.