The church's attempt to satisfy individual appetites
From Church Transformation:
The problem is not whether or not a church has a dynamic preacher, a worship band, or liturgy. The problem is that too many churches, consciously or not, have emphasized production of spiritual goods to satisfy individual appetites. As people who attend church, we may not have asked yet if we would like to add fries to the order of faith, but we have learned how to look for what we like. And if we don't find it or it mysteriously disappears, then, like the members of focus groups, the next step is obvious: Head down the road a mile or two to the next McChurch.

The reason people move on to other churches is quite apparent. Their personal needs are not being fully met at the church they were
attending.
For example, why do people go to one restaurant versus another ? They are seeking to have a personal need met at that moment. Whatever restaurant that best meets that need for that person at that moment (in that persons judgement) gets that person as a customer.
This applies equally as well to churches. If they meet the "customers" needs they get that "customers" business.
If churches would ask people who attend their church what their personal needs are and help to meet those needs they would attract more "customers". If they ignore the personal needs of people they will eventually lose that "customer".
What is needed is " personalized evangelism "
Churches need to focus on the personal needs of each person who attends their church. If they do they will attract more "customers". If they don't they will lose them.