What a lot of these articles miss is the explosive growth of non-denominational evangelical churches, many of which meet in school cafeterias, movie theaters or other rented spaces, or meet in homes. Many don’t get picked up in the statistics because they are not part of a larger body. Also, many of them tend to be very multi-ethnic. That’s where a lot of the disaffected mainliners have gone, who are still serious Christ followers but have gotten disgusted with the denominational churches.
A concrete example of how believers have left the formal church and denominations and are now meeting in non-denominational churches, such as this one in a high school gym:
This is where Christians are moving to, they are not leaving the faith.
http://www.reallife.la/blog/2016/8/18/view-from-the-bleachers