The 200,000 loss could be primarily from deaths of older members.
That is certainly a factor.
The old generation that was at church two nights a week as well as every Sunday morning is passing away.
Economic upheaval figures into this as well. Mom and dad are working multiple jobs to make ends meet - IF they are lucky enough to find them. Some families aren’t. Your local small town Baptist (or other) church that loses half a dozen key families because their jobs left is in serious hurt. The families that move away don’t automatically get replaced. Nor do they necessarily commit to a new church in their new home.