Even if your less into design and more into content strategy you may find some redeeming value with, wait for it, dummy copy, no less. Anyway, happen, not always the way you like it, not always in the preferred order.
A client that’s unhappy for a reason is a problem, a client that’s unhappy though he or her can’t quite put a finger on it is worse. To short sentences, to many headings, images too large for the proposed design, or too small.
A seemingly elegant design can quickly begin to bloat with unexpected content or break under the weight of actual activity. Fake data can ensure a nice looking layout.