In our case we were adding new APIs and expanding our format rapidly for years on end. After the 20th or so miscommunication that lead to a week+ delay because

In our case we were adding new APIs and expanding our format rapidly for years on end. After the 20th or so miscommunication that lead to a week+ delay because someone got a field order wrong, or in one case because we hit a bug in the C# compiler in regards to struct layouts (!!) we switched away from rolling our own.