Sorting is easier than deciding how to sort.
Sorting is the act of arranging content according to established rules. The act of deciding how to sort something within a taxonomy is called classification.
If you have a large pile of things, it may take a lot of time to sort through them. But sorting isn't the hard part. Classification is.
Think about sorting a bag of groceries into a pre-arranged pantry. Everything has a place. You're simply following the plan. Easy, right?
Now unload that same bag into a kitchen without rules for where things go. How much longer would it take you? How much more frustrating a task would it be? How much variation would you get when the next person unloads groceries?
Sorting is easy when clear rules are in place. But without those rules, assumptions take over and things end up in places where they can be harder to find.
The most challenging part of classification is working with other people to agree on a set of rules.