For example, one of my employers routinely tested DB restore by wiping an entire table in stage, and then having the on call restore from backup. This is trivial because you know it happened recently, you have low traffic in this instance, and you can cleanly copy over the missing table.
But the last actual production DB incident they had was a subtle data corruption bug that went unnoticed for several weeks - at which point restoring meant a painful merge of 10s of thousands of records, involving several related tables.